mirror of
https://github.com/PiBrewing/craftbeerpi4.git
synced 2024-12-29 00:41:45 +01:00
593 lines
18 KiB
Python
593 lines
18 KiB
Python
"""Common IO api utilities"""
|
|
|
|
import bz2
|
|
from collections import abc
|
|
import gzip
|
|
from io import BufferedIOBase, BytesIO, RawIOBase
|
|
import mmap
|
|
import os
|
|
import pathlib
|
|
from typing import (
|
|
IO,
|
|
TYPE_CHECKING,
|
|
Any,
|
|
AnyStr,
|
|
Dict,
|
|
List,
|
|
Mapping,
|
|
Optional,
|
|
Tuple,
|
|
Type,
|
|
Union,
|
|
)
|
|
from urllib.parse import (
|
|
urljoin,
|
|
urlparse as parse_url,
|
|
uses_netloc,
|
|
uses_params,
|
|
uses_relative,
|
|
)
|
|
import zipfile
|
|
|
|
from pandas._typing import FilePathOrBuffer
|
|
from pandas.compat import _get_lzma_file, _import_lzma
|
|
from pandas.compat._optional import import_optional_dependency
|
|
|
|
from pandas.core.dtypes.common import is_file_like
|
|
|
|
lzma = _import_lzma()
|
|
|
|
|
|
_VALID_URLS = set(uses_relative + uses_netloc + uses_params)
|
|
_VALID_URLS.discard("")
|
|
|
|
|
|
if TYPE_CHECKING:
|
|
from io import IOBase # noqa: F401
|
|
|
|
|
|
def is_url(url) -> bool:
|
|
"""
|
|
Check to see if a URL has a valid protocol.
|
|
|
|
Parameters
|
|
----------
|
|
url : str or unicode
|
|
|
|
Returns
|
|
-------
|
|
isurl : bool
|
|
If `url` has a valid protocol return True otherwise False.
|
|
"""
|
|
if not isinstance(url, str):
|
|
return False
|
|
return parse_url(url).scheme in _VALID_URLS
|
|
|
|
|
|
def _expand_user(
|
|
filepath_or_buffer: FilePathOrBuffer[AnyStr],
|
|
) -> FilePathOrBuffer[AnyStr]:
|
|
"""
|
|
Return the argument with an initial component of ~ or ~user
|
|
replaced by that user's home directory.
|
|
|
|
Parameters
|
|
----------
|
|
filepath_or_buffer : object to be converted if possible
|
|
|
|
Returns
|
|
-------
|
|
expanded_filepath_or_buffer : an expanded filepath or the
|
|
input if not expandable
|
|
"""
|
|
if isinstance(filepath_or_buffer, str):
|
|
return os.path.expanduser(filepath_or_buffer)
|
|
return filepath_or_buffer
|
|
|
|
|
|
def validate_header_arg(header) -> None:
|
|
if isinstance(header, bool):
|
|
raise TypeError(
|
|
"Passing a bool to header is invalid. Use header=None for no header or "
|
|
"header=int or list-like of ints to specify "
|
|
"the row(s) making up the column names"
|
|
)
|
|
|
|
|
|
def stringify_path(
|
|
filepath_or_buffer: FilePathOrBuffer[AnyStr],
|
|
) -> FilePathOrBuffer[AnyStr]:
|
|
"""
|
|
Attempt to convert a path-like object to a string.
|
|
|
|
Parameters
|
|
----------
|
|
filepath_or_buffer : object to be converted
|
|
|
|
Returns
|
|
-------
|
|
str_filepath_or_buffer : maybe a string version of the object
|
|
|
|
Notes
|
|
-----
|
|
Objects supporting the fspath protocol (python 3.6+) are coerced
|
|
according to its __fspath__ method.
|
|
|
|
For backwards compatibility with older pythons, pathlib.Path and
|
|
py.path objects are specially coerced.
|
|
|
|
Any other object is passed through unchanged, which includes bytes,
|
|
strings, buffers, or anything else that's not even path-like.
|
|
"""
|
|
if hasattr(filepath_or_buffer, "__fspath__"):
|
|
# https://github.com/python/mypy/issues/1424
|
|
return filepath_or_buffer.__fspath__() # type: ignore
|
|
elif isinstance(filepath_or_buffer, pathlib.Path):
|
|
return str(filepath_or_buffer)
|
|
return _expand_user(filepath_or_buffer)
|
|
|
|
|
|
def urlopen(*args, **kwargs):
|
|
"""
|
|
Lazy-import wrapper for stdlib urlopen, as that imports a big chunk of
|
|
the stdlib.
|
|
"""
|
|
import urllib.request
|
|
|
|
return urllib.request.urlopen(*args, **kwargs)
|
|
|
|
|
|
def is_fsspec_url(url: FilePathOrBuffer) -> bool:
|
|
"""
|
|
Returns true if the given URL looks like
|
|
something fsspec can handle
|
|
"""
|
|
return (
|
|
isinstance(url, str)
|
|
and "://" in url
|
|
and not url.startswith(("http://", "https://"))
|
|
)
|
|
|
|
|
|
def get_filepath_or_buffer(
|
|
filepath_or_buffer: FilePathOrBuffer,
|
|
encoding: Optional[str] = None,
|
|
compression: Optional[str] = None,
|
|
mode: Optional[str] = None,
|
|
storage_options: Optional[Dict[str, Any]] = None,
|
|
):
|
|
"""
|
|
If the filepath_or_buffer is a url, translate and return the buffer.
|
|
Otherwise passthrough.
|
|
|
|
Parameters
|
|
----------
|
|
filepath_or_buffer : a url, filepath (str, py.path.local or pathlib.Path),
|
|
or buffer
|
|
compression : {{'gzip', 'bz2', 'zip', 'xz', None}}, optional
|
|
encoding : the encoding to use to decode bytes, default is 'utf-8'
|
|
mode : str, optional
|
|
storage_options: dict, optional
|
|
passed on to fsspec, if using it; this is not yet accessed by the public API
|
|
|
|
Returns
|
|
-------
|
|
Tuple[FilePathOrBuffer, str, str, bool]
|
|
Tuple containing the filepath or buffer, the encoding, the compression
|
|
and should_close.
|
|
"""
|
|
filepath_or_buffer = stringify_path(filepath_or_buffer)
|
|
|
|
if isinstance(filepath_or_buffer, str) and is_url(filepath_or_buffer):
|
|
# TODO: fsspec can also handle HTTP via requests, but leaving this unchanged
|
|
req = urlopen(filepath_or_buffer)
|
|
content_encoding = req.headers.get("Content-Encoding", None)
|
|
if content_encoding == "gzip":
|
|
# Override compression based on Content-Encoding header
|
|
compression = "gzip"
|
|
reader = BytesIO(req.read())
|
|
req.close()
|
|
return reader, encoding, compression, True
|
|
|
|
if is_fsspec_url(filepath_or_buffer):
|
|
assert isinstance(
|
|
filepath_or_buffer, str
|
|
) # just to appease mypy for this branch
|
|
# two special-case s3-like protocols; these have special meaning in Hadoop,
|
|
# but are equivalent to just "s3" from fsspec's point of view
|
|
# cc #11071
|
|
if filepath_or_buffer.startswith("s3a://"):
|
|
filepath_or_buffer = filepath_or_buffer.replace("s3a://", "s3://")
|
|
if filepath_or_buffer.startswith("s3n://"):
|
|
filepath_or_buffer = filepath_or_buffer.replace("s3n://", "s3://")
|
|
fsspec = import_optional_dependency("fsspec")
|
|
|
|
# If botocore is installed we fallback to reading with anon=True
|
|
# to allow reads from public buckets
|
|
err_types_to_retry_with_anon: List[Any] = []
|
|
try:
|
|
import_optional_dependency("botocore")
|
|
from botocore.exceptions import ClientError, NoCredentialsError
|
|
|
|
err_types_to_retry_with_anon = [
|
|
ClientError,
|
|
NoCredentialsError,
|
|
PermissionError,
|
|
]
|
|
except ImportError:
|
|
pass
|
|
|
|
try:
|
|
file_obj = fsspec.open(
|
|
filepath_or_buffer, mode=mode or "rb", **(storage_options or {})
|
|
).open()
|
|
# GH 34626 Reads from Public Buckets without Credentials needs anon=True
|
|
except tuple(err_types_to_retry_with_anon):
|
|
if storage_options is None:
|
|
storage_options = {"anon": True}
|
|
else:
|
|
# don't mutate user input.
|
|
storage_options = dict(storage_options)
|
|
storage_options["anon"] = True
|
|
file_obj = fsspec.open(
|
|
filepath_or_buffer, mode=mode or "rb", **(storage_options or {})
|
|
).open()
|
|
|
|
return file_obj, encoding, compression, True
|
|
|
|
if isinstance(filepath_or_buffer, (str, bytes, mmap.mmap)):
|
|
return _expand_user(filepath_or_buffer), None, compression, False
|
|
|
|
if not is_file_like(filepath_or_buffer):
|
|
msg = f"Invalid file path or buffer object type: {type(filepath_or_buffer)}"
|
|
raise ValueError(msg)
|
|
|
|
return filepath_or_buffer, None, compression, False
|
|
|
|
|
|
def file_path_to_url(path: str) -> str:
|
|
"""
|
|
converts an absolute native path to a FILE URL.
|
|
|
|
Parameters
|
|
----------
|
|
path : a path in native format
|
|
|
|
Returns
|
|
-------
|
|
a valid FILE URL
|
|
"""
|
|
# lazify expensive import (~30ms)
|
|
from urllib.request import pathname2url
|
|
|
|
return urljoin("file:", pathname2url(path))
|
|
|
|
|
|
_compression_to_extension = {"gzip": ".gz", "bz2": ".bz2", "zip": ".zip", "xz": ".xz"}
|
|
|
|
|
|
def get_compression_method(
|
|
compression: Optional[Union[str, Mapping[str, str]]]
|
|
) -> Tuple[Optional[str], Dict[str, str]]:
|
|
"""
|
|
Simplifies a compression argument to a compression method string and
|
|
a mapping containing additional arguments.
|
|
|
|
Parameters
|
|
----------
|
|
compression : str or mapping
|
|
If string, specifies the compression method. If mapping, value at key
|
|
'method' specifies compression method.
|
|
|
|
Returns
|
|
-------
|
|
tuple of ({compression method}, Optional[str]
|
|
{compression arguments}, Dict[str, str])
|
|
|
|
Raises
|
|
------
|
|
ValueError on mapping missing 'method' key
|
|
"""
|
|
if isinstance(compression, Mapping):
|
|
compression_args = dict(compression)
|
|
try:
|
|
compression = compression_args.pop("method")
|
|
except KeyError as err:
|
|
raise ValueError("If mapping, compression must have key 'method'") from err
|
|
else:
|
|
compression_args = {}
|
|
return compression, compression_args
|
|
|
|
|
|
def infer_compression(
|
|
filepath_or_buffer: FilePathOrBuffer, compression: Optional[str]
|
|
) -> Optional[str]:
|
|
"""
|
|
Get the compression method for filepath_or_buffer. If compression='infer',
|
|
the inferred compression method is returned. Otherwise, the input
|
|
compression method is returned unchanged, unless it's invalid, in which
|
|
case an error is raised.
|
|
|
|
Parameters
|
|
----------
|
|
filepath_or_buffer : str or file handle
|
|
File path or object.
|
|
compression : {'infer', 'gzip', 'bz2', 'zip', 'xz', None}
|
|
If 'infer' and `filepath_or_buffer` is path-like, then detect
|
|
compression from the following extensions: '.gz', '.bz2', '.zip',
|
|
or '.xz' (otherwise no compression).
|
|
|
|
Returns
|
|
-------
|
|
string or None
|
|
|
|
Raises
|
|
------
|
|
ValueError on invalid compression specified.
|
|
"""
|
|
# No compression has been explicitly specified
|
|
if compression is None:
|
|
return None
|
|
|
|
# Infer compression
|
|
if compression == "infer":
|
|
# Convert all path types (e.g. pathlib.Path) to strings
|
|
filepath_or_buffer = stringify_path(filepath_or_buffer)
|
|
if not isinstance(filepath_or_buffer, str):
|
|
# Cannot infer compression of a buffer, assume no compression
|
|
return None
|
|
|
|
# Infer compression from the filename/URL extension
|
|
for compression, extension in _compression_to_extension.items():
|
|
if filepath_or_buffer.lower().endswith(extension):
|
|
return compression
|
|
return None
|
|
|
|
# Compression has been specified. Check that it's valid
|
|
if compression in _compression_to_extension:
|
|
return compression
|
|
|
|
msg = f"Unrecognized compression type: {compression}"
|
|
valid = ["infer", None] + sorted(_compression_to_extension)
|
|
msg += f"\nValid compression types are {valid}"
|
|
raise ValueError(msg)
|
|
|
|
|
|
def get_handle(
|
|
path_or_buf,
|
|
mode: str,
|
|
encoding=None,
|
|
compression: Optional[Union[str, Mapping[str, Any]]] = None,
|
|
memory_map: bool = False,
|
|
is_text: bool = True,
|
|
errors=None,
|
|
):
|
|
"""
|
|
Get file handle for given path/buffer and mode.
|
|
|
|
Parameters
|
|
----------
|
|
path_or_buf : str or file handle
|
|
File path or object.
|
|
mode : str
|
|
Mode to open path_or_buf with.
|
|
encoding : str or None
|
|
Encoding to use.
|
|
compression : str or dict, default None
|
|
If string, specifies compression mode. If dict, value at key 'method'
|
|
specifies compression mode. Compression mode must be one of {'infer',
|
|
'gzip', 'bz2', 'zip', 'xz', None}. If compression mode is 'infer'
|
|
and `filepath_or_buffer` is path-like, then detect compression from
|
|
the following extensions: '.gz', '.bz2', '.zip', or '.xz' (otherwise
|
|
no compression). If dict and compression mode is one of
|
|
{'zip', 'gzip', 'bz2'}, or inferred as one of the above,
|
|
other entries passed as additional compression options.
|
|
|
|
.. versionchanged:: 1.0.0
|
|
|
|
May now be a dict with key 'method' as compression mode
|
|
and other keys as compression options if compression
|
|
mode is 'zip'.
|
|
|
|
.. versionchanged:: 1.1.0
|
|
|
|
Passing compression options as keys in dict is now
|
|
supported for compression modes 'gzip' and 'bz2' as well as 'zip'.
|
|
|
|
memory_map : boolean, default False
|
|
See parsers._parser_params for more information.
|
|
is_text : boolean, default True
|
|
whether file/buffer is in text format (csv, json, etc.), or in binary
|
|
mode (pickle, etc.).
|
|
errors : str, default 'strict'
|
|
Specifies how encoding and decoding errors are to be handled.
|
|
See the errors argument for :func:`open` for a full list
|
|
of options.
|
|
|
|
.. versionadded:: 1.1.0
|
|
|
|
Returns
|
|
-------
|
|
f : file-like
|
|
A file-like object.
|
|
handles : list of file-like objects
|
|
A list of file-like object that were opened in this function.
|
|
"""
|
|
need_text_wrapping: Tuple[Type["IOBase"], ...]
|
|
try:
|
|
from s3fs import S3File
|
|
|
|
need_text_wrapping = (BufferedIOBase, RawIOBase, S3File)
|
|
except ImportError:
|
|
need_text_wrapping = (BufferedIOBase, RawIOBase)
|
|
|
|
handles: List[IO] = list()
|
|
f = path_or_buf
|
|
|
|
# Convert pathlib.Path/py.path.local or string
|
|
path_or_buf = stringify_path(path_or_buf)
|
|
is_path = isinstance(path_or_buf, str)
|
|
|
|
compression, compression_args = get_compression_method(compression)
|
|
if is_path:
|
|
compression = infer_compression(path_or_buf, compression)
|
|
|
|
if compression:
|
|
|
|
# GH33398 the type ignores here seem related to mypy issue #5382;
|
|
# it may be possible to remove them once that is resolved.
|
|
|
|
# GZ Compression
|
|
if compression == "gzip":
|
|
if is_path:
|
|
f = gzip.open(
|
|
path_or_buf, mode, **compression_args # type: ignore
|
|
)
|
|
else:
|
|
f = gzip.GzipFile(
|
|
fileobj=path_or_buf, **compression_args # type: ignore
|
|
)
|
|
|
|
# BZ Compression
|
|
elif compression == "bz2":
|
|
if is_path:
|
|
f = bz2.BZ2File(
|
|
path_or_buf, mode, **compression_args # type: ignore
|
|
)
|
|
else:
|
|
f = bz2.BZ2File(path_or_buf, **compression_args) # type: ignore
|
|
|
|
# ZIP Compression
|
|
elif compression == "zip":
|
|
zf = _BytesZipFile(path_or_buf, mode, **compression_args)
|
|
# Ensure the container is closed as well.
|
|
handles.append(zf)
|
|
if zf.mode == "w":
|
|
f = zf
|
|
elif zf.mode == "r":
|
|
zip_names = zf.namelist()
|
|
if len(zip_names) == 1:
|
|
f = zf.open(zip_names.pop())
|
|
elif len(zip_names) == 0:
|
|
raise ValueError(f"Zero files found in ZIP file {path_or_buf}")
|
|
else:
|
|
raise ValueError(
|
|
"Multiple files found in ZIP file. "
|
|
f"Only one file per ZIP: {zip_names}"
|
|
)
|
|
|
|
# XZ Compression
|
|
elif compression == "xz":
|
|
f = _get_lzma_file(lzma)(path_or_buf, mode)
|
|
|
|
# Unrecognized Compression
|
|
else:
|
|
msg = f"Unrecognized compression type: {compression}"
|
|
raise ValueError(msg)
|
|
|
|
handles.append(f)
|
|
|
|
elif is_path:
|
|
if encoding:
|
|
# Encoding
|
|
f = open(path_or_buf, mode, encoding=encoding, errors=errors, newline="")
|
|
elif is_text:
|
|
# No explicit encoding
|
|
f = open(path_or_buf, mode, errors="replace", newline="")
|
|
else:
|
|
# Binary mode
|
|
f = open(path_or_buf, mode)
|
|
handles.append(f)
|
|
|
|
# Convert BytesIO or file objects passed with an encoding
|
|
if is_text and (compression or isinstance(f, need_text_wrapping)):
|
|
from io import TextIOWrapper
|
|
|
|
g = TextIOWrapper(f, encoding=encoding, errors=errors, newline="")
|
|
if not isinstance(f, (BufferedIOBase, RawIOBase)):
|
|
handles.append(g)
|
|
f = g
|
|
|
|
if memory_map and hasattr(f, "fileno"):
|
|
try:
|
|
wrapped = _MMapWrapper(f)
|
|
f.close()
|
|
f = wrapped
|
|
except Exception:
|
|
# we catch any errors that may have occurred
|
|
# because that is consistent with the lower-level
|
|
# functionality of the C engine (pd.read_csv), so
|
|
# leave the file handler as is then
|
|
pass
|
|
|
|
return f, handles
|
|
|
|
|
|
class _BytesZipFile(zipfile.ZipFile, BytesIO): # type: ignore
|
|
"""
|
|
Wrapper for standard library class ZipFile and allow the returned file-like
|
|
handle to accept byte strings via `write` method.
|
|
|
|
BytesIO provides attributes of file-like object and ZipFile.writestr writes
|
|
bytes strings into a member of the archive.
|
|
"""
|
|
|
|
# GH 17778
|
|
def __init__(
|
|
self,
|
|
file: FilePathOrBuffer,
|
|
mode: str,
|
|
archive_name: Optional[str] = None,
|
|
**kwargs,
|
|
):
|
|
if mode in ["wb", "rb"]:
|
|
mode = mode.replace("b", "")
|
|
self.archive_name = archive_name
|
|
super().__init__(file, mode, zipfile.ZIP_DEFLATED, **kwargs)
|
|
|
|
def write(self, data):
|
|
archive_name = self.filename
|
|
if self.archive_name is not None:
|
|
archive_name = self.archive_name
|
|
super().writestr(archive_name, data)
|
|
|
|
@property
|
|
def closed(self):
|
|
return self.fp is None
|
|
|
|
|
|
class _MMapWrapper(abc.Iterator):
|
|
"""
|
|
Wrapper for the Python's mmap class so that it can be properly read in
|
|
by Python's csv.reader class.
|
|
|
|
Parameters
|
|
----------
|
|
f : file object
|
|
File object to be mapped onto memory. Must support the 'fileno'
|
|
method or have an equivalent attribute
|
|
|
|
"""
|
|
|
|
def __init__(self, f: IO):
|
|
self.mmap = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
|
|
|
|
def __getattr__(self, name: str):
|
|
return getattr(self.mmap, name)
|
|
|
|
def __iter__(self) -> "_MMapWrapper":
|
|
return self
|
|
|
|
def __next__(self) -> str:
|
|
newbytes = self.mmap.readline()
|
|
|
|
# readline returns bytes, not str, but Python's CSV reader
|
|
# expects str, so convert the output to str before continuing
|
|
newline = newbytes.decode("utf-8")
|
|
|
|
# mmap doesn't raise if reading past the allocated
|
|
# data but instead returns an empty string, so raise
|
|
# if that is returned
|
|
if newline == "":
|
|
raise StopIteration
|
|
return newline
|