1311 lines
45 KiB
Python
1311 lines
45 KiB
Python
from __future__ import annotations
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from collections import (
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abc,
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defaultdict,
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)
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import csv
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from io import StringIO
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import re
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import sys
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from typing import (
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IO,
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DefaultDict,
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Hashable,
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Iterator,
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Literal,
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Mapping,
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Sequence,
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cast,
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)
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import warnings
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import numpy as np
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import pandas._libs.lib as lib
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from pandas._typing import (
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ArrayLike,
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ReadCsvBuffer,
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Scalar,
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)
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from pandas.errors import (
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EmptyDataError,
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ParserError,
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)
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from pandas.util._exceptions import find_stack_level
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from pandas.core.dtypes.common import is_integer
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from pandas.core.dtypes.inference import is_dict_like
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from pandas.io.parsers.base_parser import (
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ParserBase,
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parser_defaults,
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)
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# BOM character (byte order mark)
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# This exists at the beginning of a file to indicate endianness
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# of a file (stream). Unfortunately, this marker screws up parsing,
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# so we need to remove it if we see it.
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_BOM = "\ufeff"
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class PythonParser(ParserBase):
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def __init__(self, f: ReadCsvBuffer[str] | list, **kwds):
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"""
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Workhorse function for processing nested list into DataFrame
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"""
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super().__init__(kwds)
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self.data: Iterator[str] | None = None
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self.buf: list = []
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self.pos = 0
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self.line_pos = 0
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self.skiprows = kwds["skiprows"]
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if callable(self.skiprows):
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self.skipfunc = self.skiprows
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else:
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self.skipfunc = lambda x: x in self.skiprows
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self.skipfooter = _validate_skipfooter_arg(kwds["skipfooter"])
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self.delimiter = kwds["delimiter"]
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self.quotechar = kwds["quotechar"]
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if isinstance(self.quotechar, str):
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self.quotechar = str(self.quotechar)
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self.escapechar = kwds["escapechar"]
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self.doublequote = kwds["doublequote"]
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self.skipinitialspace = kwds["skipinitialspace"]
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self.lineterminator = kwds["lineterminator"]
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self.quoting = kwds["quoting"]
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self.skip_blank_lines = kwds["skip_blank_lines"]
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self.names_passed = kwds["names"] or None
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self.has_index_names = False
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if "has_index_names" in kwds:
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self.has_index_names = kwds["has_index_names"]
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self.verbose = kwds["verbose"]
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self.converters = kwds["converters"]
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self.thousands = kwds["thousands"]
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self.decimal = kwds["decimal"]
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self.comment = kwds["comment"]
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# Set self.data to something that can read lines.
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if isinstance(f, list):
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# read_excel: f is a list
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self.data = cast(Iterator[str], f)
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else:
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assert hasattr(f, "readline")
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self._make_reader(f)
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# Get columns in two steps: infer from data, then
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# infer column indices from self.usecols if it is specified.
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self._col_indices: list[int] | None = None
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columns: list[list[Scalar | None]]
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(
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columns,
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self.num_original_columns,
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self.unnamed_cols,
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) = self._infer_columns()
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# Now self.columns has the set of columns that we will process.
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# The original set is stored in self.original_columns.
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# error: Cannot determine type of 'index_names'
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self.columns: list[Hashable]
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(
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self.columns,
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self.index_names,
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self.col_names,
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_,
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) = self._extract_multi_indexer_columns(
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columns,
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self.index_names, # type: ignore[has-type]
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)
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# get popped off for index
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self.orig_names: list[Hashable] = list(self.columns)
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# needs to be cleaned/refactored
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# multiple date column thing turning into a real spaghetti factory
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if not self._has_complex_date_col:
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(index_names, self.orig_names, self.columns) = self._get_index_name(
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self.columns
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)
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self._name_processed = True
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if self.index_names is None:
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self.index_names = index_names
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if self._col_indices is None:
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self._col_indices = list(range(len(self.columns)))
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self._parse_date_cols = self._validate_parse_dates_presence(self.columns)
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no_thousands_columns: set[int] | None = None
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if self.parse_dates:
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no_thousands_columns = self._set_noconvert_dtype_columns(
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self._col_indices, self.columns
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)
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self._no_thousands_columns = no_thousands_columns
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if len(self.decimal) != 1:
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raise ValueError("Only length-1 decimal markers supported")
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decimal = re.escape(self.decimal)
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if self.thousands is None:
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regex = rf"^[\-\+]?[0-9]*({decimal}[0-9]*)?([0-9]?(E|e)\-?[0-9]+)?$"
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else:
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thousands = re.escape(self.thousands)
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regex = (
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rf"^[\-\+]?([0-9]+{thousands}|[0-9])*({decimal}[0-9]*)?"
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rf"([0-9]?(E|e)\-?[0-9]+)?$"
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)
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self.num = re.compile(regex)
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def _make_reader(self, f) -> None:
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sep = self.delimiter
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if sep is None or len(sep) == 1:
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if self.lineterminator:
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raise ValueError(
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"Custom line terminators not supported in python parser (yet)"
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)
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class MyDialect(csv.Dialect):
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delimiter = self.delimiter
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quotechar = self.quotechar
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escapechar = self.escapechar
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doublequote = self.doublequote
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skipinitialspace = self.skipinitialspace
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quoting = self.quoting
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lineterminator = "\n"
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dia = MyDialect
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if sep is not None:
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dia.delimiter = sep
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else:
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# attempt to sniff the delimiter from the first valid line,
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# i.e. no comment line and not in skiprows
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line = f.readline()
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lines = self._check_comments([[line]])[0]
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while self.skipfunc(self.pos) or not lines:
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self.pos += 1
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line = f.readline()
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lines = self._check_comments([[line]])[0]
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# since `line` was a string, lines will be a list containing
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# only a single string
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line = lines[0]
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self.pos += 1
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self.line_pos += 1
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sniffed = csv.Sniffer().sniff(line)
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dia.delimiter = sniffed.delimiter
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# Note: encoding is irrelevant here
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line_rdr = csv.reader(StringIO(line), dialect=dia)
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self.buf.extend(list(line_rdr))
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# Note: encoding is irrelevant here
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reader = csv.reader(f, dialect=dia, strict=True)
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else:
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def _read():
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line = f.readline()
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pat = re.compile(sep)
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yield pat.split(line.strip())
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for line in f:
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yield pat.split(line.strip())
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reader = _read()
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# error: Incompatible types in assignment (expression has type "_reader",
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# variable has type "Union[IO[Any], RawIOBase, BufferedIOBase, TextIOBase,
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# TextIOWrapper, mmap, None]")
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self.data = reader # type: ignore[assignment]
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def read(self, rows: int | None = None):
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try:
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content = self._get_lines(rows)
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except StopIteration:
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if self._first_chunk:
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content = []
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else:
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self.close()
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raise
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# done with first read, next time raise StopIteration
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self._first_chunk = False
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columns: Sequence[Hashable] = list(self.orig_names)
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if not len(content): # pragma: no cover
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# DataFrame with the right metadata, even though it's length 0
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names = self._maybe_dedup_names(self.orig_names)
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# error: Cannot determine type of 'index_col'
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index, columns, col_dict = self._get_empty_meta(
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names,
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self.index_col, # type: ignore[has-type]
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self.index_names,
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self.dtype,
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)
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conv_columns = self._maybe_make_multi_index_columns(columns, self.col_names)
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return index, conv_columns, col_dict
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# handle new style for names in index
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count_empty_content_vals = count_empty_vals(content[0])
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indexnamerow = None
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if self.has_index_names and count_empty_content_vals == len(columns):
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indexnamerow = content[0]
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content = content[1:]
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alldata = self._rows_to_cols(content)
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data, columns = self._exclude_implicit_index(alldata)
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conv_data = self._convert_data(data)
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columns, conv_data = self._do_date_conversions(columns, conv_data)
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index, columns = self._make_index(conv_data, alldata, columns, indexnamerow)
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return index, columns, conv_data
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def _exclude_implicit_index(
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self,
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alldata: list[np.ndarray],
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) -> tuple[Mapping[Hashable, np.ndarray], Sequence[Hashable]]:
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names = self._maybe_dedup_names(self.orig_names)
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offset = 0
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if self._implicit_index:
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# error: Cannot determine type of 'index_col'
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offset = len(self.index_col) # type: ignore[has-type]
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len_alldata = len(alldata)
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self._check_data_length(names, alldata)
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return {
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name: alldata[i + offset] for i, name in enumerate(names) if i < len_alldata
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}, names
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# legacy
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def get_chunk(self, size=None):
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if size is None:
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# error: "PythonParser" has no attribute "chunksize"
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size = self.chunksize # type: ignore[attr-defined]
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return self.read(rows=size)
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def _convert_data(
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self,
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data: Mapping[Hashable, np.ndarray],
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) -> Mapping[Hashable, ArrayLike]:
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# apply converters
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clean_conv = self._clean_mapping(self.converters)
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clean_dtypes = self._clean_mapping(self.dtype)
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# Apply NA values.
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clean_na_values = {}
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clean_na_fvalues = {}
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if isinstance(self.na_values, dict):
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for col in self.na_values:
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na_value = self.na_values[col]
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na_fvalue = self.na_fvalues[col]
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if isinstance(col, int) and col not in self.orig_names:
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col = self.orig_names[col]
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clean_na_values[col] = na_value
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clean_na_fvalues[col] = na_fvalue
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else:
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clean_na_values = self.na_values
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clean_na_fvalues = self.na_fvalues
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return self._convert_to_ndarrays(
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data,
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clean_na_values,
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clean_na_fvalues,
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self.verbose,
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clean_conv,
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clean_dtypes,
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)
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def _infer_columns(
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self,
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) -> tuple[list[list[Scalar | None]], int, set[Scalar | None]]:
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names = self.names
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num_original_columns = 0
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clear_buffer = True
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unnamed_cols: set[Scalar | None] = set()
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self._header_line = None
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if self.header is not None:
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header = self.header
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if isinstance(header, (list, tuple, np.ndarray)):
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have_mi_columns = len(header) > 1
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# we have a mi columns, so read an extra line
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if have_mi_columns:
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header = list(header) + [header[-1] + 1]
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else:
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have_mi_columns = False
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header = [header]
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columns: list[list[Scalar | None]] = []
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for level, hr in enumerate(header):
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try:
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line = self._buffered_line()
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while self.line_pos <= hr:
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line = self._next_line()
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except StopIteration as err:
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if self.line_pos < hr:
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raise ValueError(
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f"Passed header={hr} but only {self.line_pos + 1} lines in "
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"file"
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) from err
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# We have an empty file, so check
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# if columns are provided. That will
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# serve as the 'line' for parsing
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if have_mi_columns and hr > 0:
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if clear_buffer:
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self._clear_buffer()
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columns.append([None] * len(columns[-1]))
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return columns, num_original_columns, unnamed_cols
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if not self.names:
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raise EmptyDataError("No columns to parse from file") from err
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line = self.names[:]
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this_columns: list[Scalar | None] = []
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this_unnamed_cols = []
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for i, c in enumerate(line):
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if c == "":
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if have_mi_columns:
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col_name = f"Unnamed: {i}_level_{level}"
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else:
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col_name = f"Unnamed: {i}"
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this_unnamed_cols.append(i)
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this_columns.append(col_name)
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else:
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this_columns.append(c)
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if not have_mi_columns and self.mangle_dupe_cols:
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counts: DefaultDict = defaultdict(int)
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# Ensure that regular columns are used before unnamed ones
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# to keep given names and mangle unnamed columns
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col_loop_order = [
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i
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for i in range(len(this_columns))
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if i not in this_unnamed_cols
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] + this_unnamed_cols
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for i in col_loop_order:
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col = this_columns[i]
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old_col = col
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cur_count = counts[col]
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if cur_count > 0:
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while cur_count > 0:
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counts[old_col] = cur_count + 1
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col = f"{old_col}.{cur_count}"
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if col in this_columns:
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cur_count += 1
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else:
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cur_count = counts[col]
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if (
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self.dtype is not None
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and is_dict_like(self.dtype)
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and self.dtype.get(old_col) is not None
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and self.dtype.get(col) is None
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):
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self.dtype.update({col: self.dtype.get(old_col)})
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this_columns[i] = col
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counts[col] = cur_count + 1
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elif have_mi_columns:
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# if we have grabbed an extra line, but its not in our
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# format so save in the buffer, and create an blank extra
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# line for the rest of the parsing code
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if hr == header[-1]:
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lc = len(this_columns)
|
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# error: Cannot determine type of 'index_col'
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sic = self.index_col # type: ignore[has-type]
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ic = len(sic) if sic is not None else 0
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unnamed_count = len(this_unnamed_cols)
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|
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# if wrong number of blanks or no index, not our format
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if (lc != unnamed_count and lc - ic > unnamed_count) or ic == 0:
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clear_buffer = False
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this_columns = [None] * lc
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self.buf = [self.buf[-1]]
|
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columns.append(this_columns)
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unnamed_cols.update({this_columns[i] for i in this_unnamed_cols})
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|
|
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if len(columns) == 1:
|
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num_original_columns = len(this_columns)
|
|
|
|
if clear_buffer:
|
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self._clear_buffer()
|
|
|
|
first_line: list[Scalar] | None
|
|
if names is not None:
|
|
# Read first row after header to check if data are longer
|
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try:
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first_line = self._next_line()
|
|
except StopIteration:
|
|
first_line = None
|
|
|
|
len_first_data_row = 0 if first_line is None else len(first_line)
|
|
|
|
if len(names) > len(columns[0]) and len(names) > len_first_data_row:
|
|
raise ValueError(
|
|
"Number of passed names did not match "
|
|
"number of header fields in the file"
|
|
)
|
|
if len(columns) > 1:
|
|
raise TypeError("Cannot pass names with multi-index columns")
|
|
|
|
if self.usecols is not None:
|
|
# Set _use_cols. We don't store columns because they are
|
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# overwritten.
|
|
self._handle_usecols(columns, names, num_original_columns)
|
|
else:
|
|
num_original_columns = len(names)
|
|
if self._col_indices is not None and len(names) != len(
|
|
self._col_indices
|
|
):
|
|
columns = [[names[i] for i in sorted(self._col_indices)]]
|
|
else:
|
|
columns = [names]
|
|
else:
|
|
columns = self._handle_usecols(
|
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columns, columns[0], num_original_columns
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)
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else:
|
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try:
|
|
line = self._buffered_line()
|
|
|
|
except StopIteration as err:
|
|
if not names:
|
|
raise EmptyDataError("No columns to parse from file") from err
|
|
|
|
line = names[:]
|
|
|
|
# Store line, otherwise it is lost for guessing the index
|
|
self._header_line = line
|
|
ncols = len(line)
|
|
num_original_columns = ncols
|
|
|
|
if not names:
|
|
if self.prefix:
|
|
columns = [[f"{self.prefix}{i}" for i in range(ncols)]]
|
|
else:
|
|
columns = [list(range(ncols))]
|
|
columns = self._handle_usecols(
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columns, columns[0], num_original_columns
|
|
)
|
|
else:
|
|
if self.usecols is None or len(names) >= num_original_columns:
|
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columns = self._handle_usecols([names], names, num_original_columns)
|
|
num_original_columns = len(names)
|
|
else:
|
|
if not callable(self.usecols) and len(names) != len(self.usecols):
|
|
raise ValueError(
|
|
"Number of passed names did not match number of "
|
|
"header fields in the file"
|
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)
|
|
# Ignore output but set used columns.
|
|
self._handle_usecols([names], names, ncols)
|
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columns = [names]
|
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num_original_columns = ncols
|
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|
|
return columns, num_original_columns, unnamed_cols
|
|
|
|
def _handle_usecols(
|
|
self,
|
|
columns: list[list[Scalar | None]],
|
|
usecols_key: list[Scalar | None],
|
|
num_original_columns: int,
|
|
) -> list[list[Scalar | None]]:
|
|
"""
|
|
Sets self._col_indices
|
|
|
|
usecols_key is used if there are string usecols.
|
|
"""
|
|
col_indices: set[int] | list[int]
|
|
if self.usecols is not None:
|
|
if callable(self.usecols):
|
|
col_indices = self._evaluate_usecols(self.usecols, usecols_key)
|
|
elif any(isinstance(u, str) for u in self.usecols):
|
|
if len(columns) > 1:
|
|
raise ValueError(
|
|
"If using multiple headers, usecols must be integers."
|
|
)
|
|
col_indices = []
|
|
|
|
for col in self.usecols:
|
|
if isinstance(col, str):
|
|
try:
|
|
col_indices.append(usecols_key.index(col))
|
|
except ValueError:
|
|
self._validate_usecols_names(self.usecols, usecols_key)
|
|
else:
|
|
col_indices.append(col)
|
|
else:
|
|
missing_usecols = [
|
|
col for col in self.usecols if col >= num_original_columns
|
|
]
|
|
if missing_usecols:
|
|
warnings.warn(
|
|
"Defining usecols with out of bounds indices is deprecated "
|
|
"and will raise a ParserError in a future version.",
|
|
FutureWarning,
|
|
stacklevel=find_stack_level(),
|
|
)
|
|
col_indices = self.usecols
|
|
|
|
columns = [
|
|
[n for i, n in enumerate(column) if i in col_indices]
|
|
for column in columns
|
|
]
|
|
self._col_indices = sorted(col_indices)
|
|
return columns
|
|
|
|
def _buffered_line(self):
|
|
"""
|
|
Return a line from buffer, filling buffer if required.
|
|
"""
|
|
if len(self.buf) > 0:
|
|
return self.buf[0]
|
|
else:
|
|
return self._next_line()
|
|
|
|
def _check_for_bom(self, first_row: list[Scalar]) -> list[Scalar]:
|
|
"""
|
|
Checks whether the file begins with the BOM character.
|
|
If it does, remove it. In addition, if there is quoting
|
|
in the field subsequent to the BOM, remove it as well
|
|
because it technically takes place at the beginning of
|
|
the name, not the middle of it.
|
|
"""
|
|
# first_row will be a list, so we need to check
|
|
# that that list is not empty before proceeding.
|
|
if not first_row:
|
|
return first_row
|
|
|
|
# The first element of this row is the one that could have the
|
|
# BOM that we want to remove. Check that the first element is a
|
|
# string before proceeding.
|
|
if not isinstance(first_row[0], str):
|
|
return first_row
|
|
|
|
# Check that the string is not empty, as that would
|
|
# obviously not have a BOM at the start of it.
|
|
if not first_row[0]:
|
|
return first_row
|
|
|
|
# Since the string is non-empty, check that it does
|
|
# in fact begin with a BOM.
|
|
first_elt = first_row[0][0]
|
|
if first_elt != _BOM:
|
|
return first_row
|
|
|
|
first_row_bom = first_row[0]
|
|
new_row: str
|
|
|
|
if len(first_row_bom) > 1 and first_row_bom[1] == self.quotechar:
|
|
start = 2
|
|
quote = first_row_bom[1]
|
|
end = first_row_bom[2:].index(quote) + 2
|
|
|
|
# Extract the data between the quotation marks
|
|
new_row = first_row_bom[start:end]
|
|
|
|
# Extract any remaining data after the second
|
|
# quotation mark.
|
|
if len(first_row_bom) > end + 1:
|
|
new_row += first_row_bom[end + 1 :]
|
|
|
|
else:
|
|
|
|
# No quotation so just remove BOM from first element
|
|
new_row = first_row_bom[1:]
|
|
|
|
new_row_list: list[Scalar] = [new_row]
|
|
return new_row_list + first_row[1:]
|
|
|
|
def _is_line_empty(self, line: list[Scalar]) -> bool:
|
|
"""
|
|
Check if a line is empty or not.
|
|
|
|
Parameters
|
|
----------
|
|
line : str, array-like
|
|
The line of data to check.
|
|
|
|
Returns
|
|
-------
|
|
boolean : Whether or not the line is empty.
|
|
"""
|
|
return not line or all(not x for x in line)
|
|
|
|
def _next_line(self) -> list[Scalar]:
|
|
if isinstance(self.data, list):
|
|
while self.skipfunc(self.pos):
|
|
self.pos += 1
|
|
|
|
while True:
|
|
try:
|
|
line = self._check_comments([self.data[self.pos]])[0]
|
|
self.pos += 1
|
|
# either uncommented or blank to begin with
|
|
if not self.skip_blank_lines and (
|
|
self._is_line_empty(self.data[self.pos - 1]) or line
|
|
):
|
|
break
|
|
elif self.skip_blank_lines:
|
|
ret = self._remove_empty_lines([line])
|
|
if ret:
|
|
line = ret[0]
|
|
break
|
|
except IndexError:
|
|
raise StopIteration
|
|
else:
|
|
while self.skipfunc(self.pos):
|
|
self.pos += 1
|
|
# assert for mypy, data is Iterator[str] or None, would error in next
|
|
assert self.data is not None
|
|
next(self.data)
|
|
|
|
while True:
|
|
orig_line = self._next_iter_line(row_num=self.pos + 1)
|
|
self.pos += 1
|
|
|
|
if orig_line is not None:
|
|
line = self._check_comments([orig_line])[0]
|
|
|
|
if self.skip_blank_lines:
|
|
ret = self._remove_empty_lines([line])
|
|
|
|
if ret:
|
|
line = ret[0]
|
|
break
|
|
elif self._is_line_empty(orig_line) or line:
|
|
break
|
|
|
|
# This was the first line of the file,
|
|
# which could contain the BOM at the
|
|
# beginning of it.
|
|
if self.pos == 1:
|
|
line = self._check_for_bom(line)
|
|
|
|
self.line_pos += 1
|
|
self.buf.append(line)
|
|
return line
|
|
|
|
def _alert_malformed(self, msg: str, row_num: int) -> None:
|
|
"""
|
|
Alert a user about a malformed row, depending on value of
|
|
`self.on_bad_lines` enum.
|
|
|
|
If `self.on_bad_lines` is ERROR, the alert will be `ParserError`.
|
|
If `self.on_bad_lines` is WARN, the alert will be printed out.
|
|
|
|
Parameters
|
|
----------
|
|
msg: str
|
|
The error message to display.
|
|
row_num: int
|
|
The row number where the parsing error occurred.
|
|
Because this row number is displayed, we 1-index,
|
|
even though we 0-index internally.
|
|
"""
|
|
if self.on_bad_lines == self.BadLineHandleMethod.ERROR:
|
|
raise ParserError(msg)
|
|
elif self.on_bad_lines == self.BadLineHandleMethod.WARN:
|
|
base = f"Skipping line {row_num}: "
|
|
sys.stderr.write(base + msg + "\n")
|
|
|
|
def _next_iter_line(self, row_num: int) -> list[Scalar] | None:
|
|
"""
|
|
Wrapper around iterating through `self.data` (CSV source).
|
|
|
|
When a CSV error is raised, we check for specific
|
|
error messages that allow us to customize the
|
|
error message displayed to the user.
|
|
|
|
Parameters
|
|
----------
|
|
row_num: int
|
|
The row number of the line being parsed.
|
|
"""
|
|
try:
|
|
# assert for mypy, data is Iterator[str] or None, would error in next
|
|
assert self.data is not None
|
|
line = next(self.data)
|
|
# for mypy
|
|
assert isinstance(line, list)
|
|
return line
|
|
except csv.Error as e:
|
|
if (
|
|
self.on_bad_lines == self.BadLineHandleMethod.ERROR
|
|
or self.on_bad_lines == self.BadLineHandleMethod.WARN
|
|
):
|
|
msg = str(e)
|
|
|
|
if "NULL byte" in msg or "line contains NUL" in msg:
|
|
msg = (
|
|
"NULL byte detected. This byte "
|
|
"cannot be processed in Python's "
|
|
"native csv library at the moment, "
|
|
"so please pass in engine='c' instead"
|
|
)
|
|
|
|
if self.skipfooter > 0:
|
|
reason = (
|
|
"Error could possibly be due to "
|
|
"parsing errors in the skipped footer rows "
|
|
"(the skipfooter keyword is only applied "
|
|
"after Python's csv library has parsed "
|
|
"all rows)."
|
|
)
|
|
msg += ". " + reason
|
|
|
|
self._alert_malformed(msg, row_num)
|
|
return None
|
|
|
|
def _check_comments(self, lines: list[list[Scalar]]) -> list[list[Scalar]]:
|
|
if self.comment is None:
|
|
return lines
|
|
ret = []
|
|
for line in lines:
|
|
rl = []
|
|
for x in line:
|
|
if (
|
|
not isinstance(x, str)
|
|
or self.comment not in x
|
|
or x in self.na_values
|
|
):
|
|
rl.append(x)
|
|
else:
|
|
x = x[: x.find(self.comment)]
|
|
if len(x) > 0:
|
|
rl.append(x)
|
|
break
|
|
ret.append(rl)
|
|
return ret
|
|
|
|
def _remove_empty_lines(self, lines: list[list[Scalar]]) -> list[list[Scalar]]:
|
|
"""
|
|
Iterate through the lines and remove any that are
|
|
either empty or contain only one whitespace value
|
|
|
|
Parameters
|
|
----------
|
|
lines : list of list of Scalars
|
|
The array of lines that we are to filter.
|
|
|
|
Returns
|
|
-------
|
|
filtered_lines : list of list of Scalars
|
|
The same array of lines with the "empty" ones removed.
|
|
"""
|
|
ret = []
|
|
for line in lines:
|
|
# Remove empty lines and lines with only one whitespace value
|
|
if (
|
|
len(line) > 1
|
|
or len(line) == 1
|
|
and (not isinstance(line[0], str) or line[0].strip())
|
|
):
|
|
ret.append(line)
|
|
return ret
|
|
|
|
def _check_thousands(self, lines: list[list[Scalar]]) -> list[list[Scalar]]:
|
|
if self.thousands is None:
|
|
return lines
|
|
|
|
return self._search_replace_num_columns(
|
|
lines=lines, search=self.thousands, replace=""
|
|
)
|
|
|
|
def _search_replace_num_columns(
|
|
self, lines: list[list[Scalar]], search: str, replace: str
|
|
) -> list[list[Scalar]]:
|
|
ret = []
|
|
for line in lines:
|
|
rl = []
|
|
for i, x in enumerate(line):
|
|
if (
|
|
not isinstance(x, str)
|
|
or search not in x
|
|
or (self._no_thousands_columns and i in self._no_thousands_columns)
|
|
or not self.num.search(x.strip())
|
|
):
|
|
rl.append(x)
|
|
else:
|
|
rl.append(x.replace(search, replace))
|
|
ret.append(rl)
|
|
return ret
|
|
|
|
def _check_decimal(self, lines: list[list[Scalar]]) -> list[list[Scalar]]:
|
|
if self.decimal == parser_defaults["decimal"]:
|
|
return lines
|
|
|
|
return self._search_replace_num_columns(
|
|
lines=lines, search=self.decimal, replace="."
|
|
)
|
|
|
|
def _clear_buffer(self) -> None:
|
|
self.buf = []
|
|
|
|
_implicit_index = False
|
|
|
|
def _get_index_name(self, columns: list[Hashable]):
|
|
"""
|
|
Try several cases to get lines:
|
|
|
|
0) There are headers on row 0 and row 1 and their
|
|
total summed lengths equals the length of the next line.
|
|
Treat row 0 as columns and row 1 as indices
|
|
1) Look for implicit index: there are more columns
|
|
on row 1 than row 0. If this is true, assume that row
|
|
1 lists index columns and row 0 lists normal columns.
|
|
2) Get index from the columns if it was listed.
|
|
"""
|
|
orig_names = list(columns)
|
|
columns = list(columns)
|
|
|
|
line: list[Scalar] | None
|
|
if self._header_line is not None:
|
|
line = self._header_line
|
|
else:
|
|
try:
|
|
line = self._next_line()
|
|
except StopIteration:
|
|
line = None
|
|
|
|
next_line: list[Scalar] | None
|
|
try:
|
|
next_line = self._next_line()
|
|
except StopIteration:
|
|
next_line = None
|
|
|
|
# implicitly index_col=0 b/c 1 fewer column names
|
|
implicit_first_cols = 0
|
|
if line is not None:
|
|
# leave it 0, #2442
|
|
# Case 1
|
|
# error: Cannot determine type of 'index_col'
|
|
index_col = self.index_col # type: ignore[has-type]
|
|
if index_col is not False:
|
|
implicit_first_cols = len(line) - self.num_original_columns
|
|
|
|
# Case 0
|
|
if next_line is not None and self.header is not None:
|
|
if len(next_line) == len(line) + self.num_original_columns:
|
|
# column and index names on diff rows
|
|
self.index_col = list(range(len(line)))
|
|
self.buf = self.buf[1:]
|
|
|
|
for c in reversed(line):
|
|
columns.insert(0, c)
|
|
|
|
# Update list of original names to include all indices.
|
|
orig_names = list(columns)
|
|
self.num_original_columns = len(columns)
|
|
return line, orig_names, columns
|
|
|
|
if implicit_first_cols > 0:
|
|
# Case 1
|
|
self._implicit_index = True
|
|
if self.index_col is None:
|
|
self.index_col = list(range(implicit_first_cols))
|
|
|
|
index_name = None
|
|
|
|
else:
|
|
# Case 2
|
|
(index_name, columns_, self.index_col) = self._clean_index_names(
|
|
columns, self.index_col, self.unnamed_cols
|
|
)
|
|
|
|
return index_name, orig_names, columns
|
|
|
|
def _rows_to_cols(self, content: list[list[Scalar]]) -> list[np.ndarray]:
|
|
col_len = self.num_original_columns
|
|
|
|
if self._implicit_index:
|
|
col_len += len(self.index_col)
|
|
|
|
max_len = max(len(row) for row in content)
|
|
|
|
# Check that there are no rows with too many
|
|
# elements in their row (rows with too few
|
|
# elements are padded with NaN).
|
|
# error: Non-overlapping identity check (left operand type: "List[int]",
|
|
# right operand type: "Literal[False]")
|
|
if (
|
|
max_len > col_len
|
|
and self.index_col is not False # type: ignore[comparison-overlap]
|
|
and self.usecols is None
|
|
):
|
|
|
|
footers = self.skipfooter if self.skipfooter else 0
|
|
bad_lines = []
|
|
|
|
iter_content = enumerate(content)
|
|
content_len = len(content)
|
|
content = []
|
|
|
|
for (i, l) in iter_content:
|
|
actual_len = len(l)
|
|
|
|
if actual_len > col_len:
|
|
if callable(self.on_bad_lines):
|
|
new_l = self.on_bad_lines(l)
|
|
if new_l is not None:
|
|
content.append(new_l)
|
|
elif (
|
|
self.on_bad_lines == self.BadLineHandleMethod.ERROR
|
|
or self.on_bad_lines == self.BadLineHandleMethod.WARN
|
|
):
|
|
row_num = self.pos - (content_len - i + footers)
|
|
bad_lines.append((row_num, actual_len))
|
|
|
|
if self.on_bad_lines == self.BadLineHandleMethod.ERROR:
|
|
break
|
|
else:
|
|
content.append(l)
|
|
|
|
for row_num, actual_len in bad_lines:
|
|
msg = (
|
|
f"Expected {col_len} fields in line {row_num + 1}, saw "
|
|
f"{actual_len}"
|
|
)
|
|
if (
|
|
self.delimiter
|
|
and len(self.delimiter) > 1
|
|
and self.quoting != csv.QUOTE_NONE
|
|
):
|
|
# see gh-13374
|
|
reason = (
|
|
"Error could possibly be due to quotes being "
|
|
"ignored when a multi-char delimiter is used."
|
|
)
|
|
msg += ". " + reason
|
|
|
|
self._alert_malformed(msg, row_num + 1)
|
|
|
|
# see gh-13320
|
|
zipped_content = list(lib.to_object_array(content, min_width=col_len).T)
|
|
|
|
if self.usecols:
|
|
assert self._col_indices is not None
|
|
col_indices = self._col_indices
|
|
|
|
if self._implicit_index:
|
|
zipped_content = [
|
|
a
|
|
for i, a in enumerate(zipped_content)
|
|
if (
|
|
i < len(self.index_col)
|
|
or i - len(self.index_col) in col_indices
|
|
)
|
|
]
|
|
else:
|
|
zipped_content = [
|
|
a for i, a in enumerate(zipped_content) if i in col_indices
|
|
]
|
|
return zipped_content
|
|
|
|
def _get_lines(self, rows: int | None = None):
|
|
lines = self.buf
|
|
new_rows = None
|
|
|
|
# already fetched some number
|
|
if rows is not None:
|
|
# we already have the lines in the buffer
|
|
if len(self.buf) >= rows:
|
|
new_rows, self.buf = self.buf[:rows], self.buf[rows:]
|
|
|
|
# need some lines
|
|
else:
|
|
rows -= len(self.buf)
|
|
|
|
if new_rows is None:
|
|
if isinstance(self.data, list):
|
|
if self.pos > len(self.data):
|
|
raise StopIteration
|
|
if rows is None:
|
|
new_rows = self.data[self.pos :]
|
|
new_pos = len(self.data)
|
|
else:
|
|
new_rows = self.data[self.pos : self.pos + rows]
|
|
new_pos = self.pos + rows
|
|
|
|
new_rows = self._remove_skipped_rows(new_rows)
|
|
lines.extend(new_rows)
|
|
self.pos = new_pos
|
|
|
|
else:
|
|
new_rows = []
|
|
try:
|
|
if rows is not None:
|
|
|
|
rows_to_skip = 0
|
|
if self.skiprows is not None and self.pos is not None:
|
|
# Only read additional rows if pos is in skiprows
|
|
rows_to_skip = len(
|
|
set(self.skiprows) - set(range(self.pos))
|
|
)
|
|
|
|
for _ in range(rows + rows_to_skip):
|
|
# assert for mypy, data is Iterator[str] or None, would
|
|
# error in next
|
|
assert self.data is not None
|
|
new_rows.append(next(self.data))
|
|
|
|
len_new_rows = len(new_rows)
|
|
new_rows = self._remove_skipped_rows(new_rows)
|
|
lines.extend(new_rows)
|
|
else:
|
|
rows = 0
|
|
|
|
while True:
|
|
new_row = self._next_iter_line(row_num=self.pos + rows + 1)
|
|
rows += 1
|
|
|
|
if new_row is not None:
|
|
new_rows.append(new_row)
|
|
len_new_rows = len(new_rows)
|
|
|
|
except StopIteration:
|
|
len_new_rows = len(new_rows)
|
|
new_rows = self._remove_skipped_rows(new_rows)
|
|
lines.extend(new_rows)
|
|
if len(lines) == 0:
|
|
raise
|
|
self.pos += len_new_rows
|
|
|
|
self.buf = []
|
|
else:
|
|
lines = new_rows
|
|
|
|
if self.skipfooter:
|
|
lines = lines[: -self.skipfooter]
|
|
|
|
lines = self._check_comments(lines)
|
|
if self.skip_blank_lines:
|
|
lines = self._remove_empty_lines(lines)
|
|
lines = self._check_thousands(lines)
|
|
return self._check_decimal(lines)
|
|
|
|
def _remove_skipped_rows(self, new_rows: list[list[Scalar]]) -> list[list[Scalar]]:
|
|
if self.skiprows:
|
|
return [
|
|
row for i, row in enumerate(new_rows) if not self.skipfunc(i + self.pos)
|
|
]
|
|
return new_rows
|
|
|
|
|
|
class FixedWidthReader(abc.Iterator):
|
|
"""
|
|
A reader of fixed-width lines.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
f: IO[str],
|
|
colspecs: list[tuple[int, int]] | Literal["infer"],
|
|
delimiter: str | None,
|
|
comment: str | None,
|
|
skiprows: set[int] | None = None,
|
|
infer_nrows: int = 100,
|
|
) -> None:
|
|
self.f = f
|
|
self.buffer: Iterator | None = None
|
|
self.delimiter = "\r\n" + delimiter if delimiter else "\n\r\t "
|
|
self.comment = comment
|
|
if colspecs == "infer":
|
|
self.colspecs = self.detect_colspecs(
|
|
infer_nrows=infer_nrows, skiprows=skiprows
|
|
)
|
|
else:
|
|
self.colspecs = colspecs
|
|
|
|
if not isinstance(self.colspecs, (tuple, list)):
|
|
raise TypeError(
|
|
"column specifications must be a list or tuple, "
|
|
f"input was a {type(colspecs).__name__}"
|
|
)
|
|
|
|
for colspec in self.colspecs:
|
|
if not (
|
|
isinstance(colspec, (tuple, list))
|
|
and len(colspec) == 2
|
|
and isinstance(colspec[0], (int, np.integer, type(None)))
|
|
and isinstance(colspec[1], (int, np.integer, type(None)))
|
|
):
|
|
raise TypeError(
|
|
"Each column specification must be "
|
|
"2 element tuple or list of integers"
|
|
)
|
|
|
|
def get_rows(self, infer_nrows: int, skiprows: set[int] | None = None) -> list[str]:
|
|
"""
|
|
Read rows from self.f, skipping as specified.
|
|
|
|
We distinguish buffer_rows (the first <= infer_nrows
|
|
lines) from the rows returned to detect_colspecs
|
|
because it's simpler to leave the other locations
|
|
with skiprows logic alone than to modify them to
|
|
deal with the fact we skipped some rows here as
|
|
well.
|
|
|
|
Parameters
|
|
----------
|
|
infer_nrows : int
|
|
Number of rows to read from self.f, not counting
|
|
rows that are skipped.
|
|
skiprows: set, optional
|
|
Indices of rows to skip.
|
|
|
|
Returns
|
|
-------
|
|
detect_rows : list of str
|
|
A list containing the rows to read.
|
|
|
|
"""
|
|
if skiprows is None:
|
|
skiprows = set()
|
|
buffer_rows = []
|
|
detect_rows = []
|
|
for i, row in enumerate(self.f):
|
|
if i not in skiprows:
|
|
detect_rows.append(row)
|
|
buffer_rows.append(row)
|
|
if len(detect_rows) >= infer_nrows:
|
|
break
|
|
self.buffer = iter(buffer_rows)
|
|
return detect_rows
|
|
|
|
def detect_colspecs(
|
|
self, infer_nrows: int = 100, skiprows: set[int] | None = None
|
|
) -> list[tuple[int, int]]:
|
|
# Regex escape the delimiters
|
|
delimiters = "".join([rf"\{x}" for x in self.delimiter])
|
|
pattern = re.compile(f"([^{delimiters}]+)")
|
|
rows = self.get_rows(infer_nrows, skiprows)
|
|
if not rows:
|
|
raise EmptyDataError("No rows from which to infer column width")
|
|
max_len = max(map(len, rows))
|
|
mask = np.zeros(max_len + 1, dtype=int)
|
|
if self.comment is not None:
|
|
rows = [row.partition(self.comment)[0] for row in rows]
|
|
for row in rows:
|
|
for m in pattern.finditer(row):
|
|
mask[m.start() : m.end()] = 1
|
|
shifted = np.roll(mask, 1)
|
|
shifted[0] = 0
|
|
edges = np.where((mask ^ shifted) == 1)[0]
|
|
edge_pairs = list(zip(edges[::2], edges[1::2]))
|
|
return edge_pairs
|
|
|
|
def __next__(self) -> list[str]:
|
|
if self.buffer is not None:
|
|
try:
|
|
line = next(self.buffer)
|
|
except StopIteration:
|
|
self.buffer = None
|
|
line = next(self.f)
|
|
else:
|
|
line = next(self.f)
|
|
# Note: 'colspecs' is a sequence of half-open intervals.
|
|
return [line[fromm:to].strip(self.delimiter) for (fromm, to) in self.colspecs]
|
|
|
|
|
|
class FixedWidthFieldParser(PythonParser):
|
|
"""
|
|
Specialization that Converts fixed-width fields into DataFrames.
|
|
See PythonParser for details.
|
|
"""
|
|
|
|
def __init__(self, f: ReadCsvBuffer[str], **kwds) -> None:
|
|
# Support iterators, convert to a list.
|
|
self.colspecs = kwds.pop("colspecs")
|
|
self.infer_nrows = kwds.pop("infer_nrows")
|
|
PythonParser.__init__(self, f, **kwds)
|
|
|
|
def _make_reader(self, f: IO[str]) -> None:
|
|
self.data = FixedWidthReader(
|
|
f,
|
|
self.colspecs,
|
|
self.delimiter,
|
|
self.comment,
|
|
self.skiprows,
|
|
self.infer_nrows,
|
|
)
|
|
|
|
def _remove_empty_lines(self, lines: list[list[Scalar]]) -> list[list[Scalar]]:
|
|
"""
|
|
Returns the list of lines without the empty ones. With fixed-width
|
|
fields, empty lines become arrays of empty strings.
|
|
|
|
See PythonParser._remove_empty_lines.
|
|
"""
|
|
return [
|
|
line
|
|
for line in lines
|
|
if any(not isinstance(e, str) or e.strip() for e in line)
|
|
]
|
|
|
|
|
|
def count_empty_vals(vals) -> int:
|
|
return sum(1 for v in vals if v == "" or v is None)
|
|
|
|
|
|
def _validate_skipfooter_arg(skipfooter: int) -> int:
|
|
"""
|
|
Validate the 'skipfooter' parameter.
|
|
|
|
Checks whether 'skipfooter' is a non-negative integer.
|
|
Raises a ValueError if that is not the case.
|
|
|
|
Parameters
|
|
----------
|
|
skipfooter : non-negative integer
|
|
The number of rows to skip at the end of the file.
|
|
|
|
Returns
|
|
-------
|
|
validated_skipfooter : non-negative integer
|
|
The original input if the validation succeeds.
|
|
|
|
Raises
|
|
------
|
|
ValueError : 'skipfooter' was not a non-negative integer.
|
|
"""
|
|
if not is_integer(skipfooter):
|
|
raise ValueError("skipfooter must be an integer")
|
|
|
|
if skipfooter < 0:
|
|
raise ValueError("skipfooter cannot be negative")
|
|
|
|
return skipfooter
|