Files
DocsGPT/application/parser/file/tabular_parser.py
T

272 lines
9.5 KiB
Python

"""Tabular parser.
Contains parsers for tabular data files.
"""
import datetime
from pathlib import Path
from typing import Any, Dict, List, Union
from application.parser.file.base_parser import BaseParser
def cell_to_text(value: Any) -> str:
"""Render one spreadsheet/CSV cell as text that is always safe to join.
``Series.astype(str)`` cannot be trusted for this. Up to pandas 2.x it
rendered missing values as the string ``"nan"``; pandas 3.0 *preserves*
them, so ``.tolist()`` hands back Python ``float`` NaNs and ``str.join``
raises ``TypeError: sequence item N: expected str instance, float found``.
A single blank cell anywhere in a sheet was therefore enough to destroy
an entire upload.
Missing values (blank cells, ``NaT``, Excel error values, and formulas
with no cached result) become the empty string. Dates and times are
rendered ISO-8601 rather than pandas' repr. Integral floats drop the
``.0`` that pandas adds when a blank upcasts an integer column — an ID
column with one gap otherwise turns every id into ``1001.0``. NUL bytes
are stripped here because they crash the downstream Postgres text write.
Args:
value: A single cell value, of any type pandas or openpyxl may yield.
Returns:
str: The cell rendered as text; ``""`` for missing values.
"""
if value is None:
return ""
# NaN is the only float that is not equal to itself. Checked before the
# pandas call because it is by far the common case and needs no import.
if isinstance(value, float) and value != value:
return ""
try:
import pandas as pd
# Raises on array-like cells, which are legitimate values, not NA.
if pd.isna(value):
return ""
except (ImportError, TypeError, ValueError):
pass
if isinstance(value, (datetime.datetime, datetime.date, datetime.time)):
return value.isoformat()
if isinstance(value, float) and value.is_integer():
return str(int(value))
text = str(value)
return text.replace("\x00", "") if "\x00" in text else text
def _row_to_texts(row: Any) -> List[str]:
"""Render a pandas row as a list of join-safe strings."""
return [cell_to_text(v) for v in row.tolist()]
class CSVParser(BaseParser):
"""CSV parser.
Args:
concat_rows (bool): whether to concatenate all rows into one document.
If set to False, a Document will be created for each row.
True by default.
"""
def __init__(self, *args: Any, concat_rows: bool = True, **kwargs: Any) -> None:
"""Init params."""
super().__init__(*args, **kwargs)
self._concat_rows = concat_rows
def _init_parser(self) -> Dict:
"""Init parser."""
return {}
def parse_file(self, file: Path, errors: str = "ignore") -> Union[str, List[str]]:
"""Parse file.
Returns:
Union[str, List[str]]: a string or a List of strings.
"""
try:
import csv
except ImportError:
raise ValueError("csv module is required to read CSV files.")
text_list = []
with open(file, "r") as fp:
csv_reader = csv.reader(fp)
for row in csv_reader:
text_list.append(", ".join(row))
if self._concat_rows:
return "\n".join(text_list)
else:
return text_list
class PandasCSVParser(BaseParser):
r"""Pandas-based CSV parser.
Parses CSVs using the separator detection from Pandas `read_csv`function.
If special parameters are required, use the `pandas_config` dict.
Args:
concat_rows (bool): whether to concatenate all rows into one document.
If set to False, a Document will be created for each row.
True by default.
col_joiner (str): Separator to use for joining cols per row.
Set to ", " by default.
row_joiner (str): Separator to use for joining each row.
Only used when `concat_rows=True`.
Set to "\n" by default.
pandas_config (dict): Options for the `pandas.read_csv` function call.
Refer to https://pandas.pydata.org/docs/reference/api/pandas.read_csv.html
for more information.
Set to empty dict by default, this means pandas will try to figure
out the separators, table head, etc. on its own.
header_period (int): Controls how headers are included in output:
- 0: Headers only at the beginning
- 1: Headers in every row
- N > 1: Headers every N rows
header_prefix (str): Prefix for header rows. Default is "HEADERS: ".
"""
def __init__(
self,
*args: Any,
concat_rows: bool = True,
col_joiner: str = ", ",
row_joiner: str = "\n",
pandas_config: dict = {},
header_period: int = 20,
header_prefix: str = "HEADERS: ",
**kwargs: Any
) -> None:
"""Init params."""
super().__init__(*args, **kwargs)
self._concat_rows = concat_rows
self._col_joiner = col_joiner
self._row_joiner = row_joiner
self._pandas_config = pandas_config
self._header_period = header_period
self._header_prefix = header_prefix
def _init_parser(self) -> Dict:
"""Init parser."""
return {}
def parse_file(self, file: Path, errors: str = "ignore") -> Union[str, List[str]]:
"""Parse file."""
try:
import pandas as pd
except ImportError:
raise ValueError("pandas module is required to read CSV files.")
df = pd.read_csv(file, **self._pandas_config)
headers = [cell_to_text(h) for h in df.columns.tolist()]
header_row = f"{self._header_prefix}{self._col_joiner.join(headers)}"
if not self._concat_rows:
return df.apply(
lambda row: (self._col_joiner).join(_row_to_texts(row)), axis=1
).tolist()
text_list = []
if self._header_period != 1:
text_list.append(header_row)
for i, row in df.iterrows():
if (self._header_period > 1 and i > 0 and i % self._header_period == 0):
text_list.append(header_row)
text_list.append(self._col_joiner.join(_row_to_texts(row)))
if self._header_period == 1 and i < len(df) - 1:
text_list.append(header_row)
return self._row_joiner.join(text_list)
class ExcelParser(BaseParser):
r"""Excel (.xlsx) parser.
Parses Excel files using Pandas `read_excel` function.
If special parameters are required, use the `pandas_config` dict.
Args:
concat_rows (bool): whether to concatenate all rows into one document.
If set to False, a Document will be created for each row.
True by default.
col_joiner (str): Separator to use for joining cols per row.
Set to ", " by default.
row_joiner (str): Separator to use for joining each row.
Only used when `concat_rows=True`.
Set to "\n" by default.
pandas_config (dict): Options for the `pandas.read_excel` function call.
Refer to https://pandas.pydata.org/docs/reference/api/pandas.read_excel.html
for more information.
Set to empty dict by default, this means pandas will try to figure
out the table structure on its own.
header_period (int): Controls how headers are included in output:
- 0: Headers only at the beginning (default)
- 1: Headers in every row
- N > 1: Headers every N rows
header_prefix (str): Prefix for header rows. Default is "HEADERS: ".
"""
def __init__(
self,
*args: Any,
concat_rows: bool = True,
col_joiner: str = ", ",
row_joiner: str = "\n",
pandas_config: dict = {},
header_period: int = 20,
header_prefix: str = "HEADERS: ",
**kwargs: Any
) -> None:
"""Init params."""
super().__init__(*args, **kwargs)
self._concat_rows = concat_rows
self._col_joiner = col_joiner
self._row_joiner = row_joiner
self._pandas_config = pandas_config
self._header_period = header_period
self._header_prefix = header_prefix
def _init_parser(self) -> Dict:
"""Init parser."""
return {}
def parse_file(self, file: Path, errors: str = "ignore") -> Union[str, List[str]]:
"""Parse file."""
try:
import pandas as pd
except ImportError:
raise ValueError("pandas module is required to read Excel files.")
df = pd.read_excel(file, **self._pandas_config)
headers = [cell_to_text(h) for h in df.columns.tolist()]
header_row = f"{self._header_prefix}{self._col_joiner.join(headers)}"
if not self._concat_rows:
return df.apply(
lambda row: (self._col_joiner).join(_row_to_texts(row)), axis=1
).tolist()
text_list = []
if self._header_period != 1:
text_list.append(header_row)
for i, row in df.iterrows():
if (self._header_period > 1 and i > 0 and i % self._header_period == 0):
text_list.append(header_row)
text_list.append(self._col_joiner.join(_row_to_texts(row)))
if self._header_period == 1 and i < len(df) - 1:
text_list.append(header_row)
return self._row_joiner.join(text_list)