You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
489 lines
17 KiB
489 lines
17 KiB
# $Id: io.py 8228 2018-09-09 18:57:00Z grubert $
|
|
# Author: David Goodger <goodger@python.org>
|
|
# Copyright: This module has been placed in the public domain.
|
|
|
|
"""
|
|
I/O classes provide a uniform API for low-level input and output. Subclasses
|
|
exist for a variety of input/output mechanisms.
|
|
"""
|
|
|
|
__docformat__ = 'reStructuredText'
|
|
|
|
import sys
|
|
import os
|
|
import re
|
|
import codecs
|
|
from docutils import TransformSpec
|
|
from docutils.utils.error_reporting import locale_encoding, ErrorString, ErrorOutput
|
|
|
|
|
|
class InputError(IOError): pass
|
|
class OutputError(IOError): pass
|
|
|
|
def check_encoding(stream, encoding):
|
|
"""Test, whether the encoding of `stream` matches `encoding`.
|
|
|
|
Returns
|
|
|
|
:None: if `encoding` or `stream.encoding` are not a valid encoding
|
|
argument (e.g. ``None``) or `stream.encoding is missing.
|
|
:True: if the encoding argument resolves to the same value as `encoding`,
|
|
:False: if the encodings differ.
|
|
"""
|
|
try:
|
|
return codecs.lookup(stream.encoding) == codecs.lookup(encoding)
|
|
except (LookupError, AttributeError, TypeError):
|
|
return None
|
|
|
|
|
|
class Input(TransformSpec):
|
|
|
|
"""
|
|
Abstract base class for input wrappers.
|
|
"""
|
|
|
|
component_type = 'input'
|
|
|
|
default_source_path = None
|
|
|
|
def __init__(self, source=None, source_path=None, encoding=None,
|
|
error_handler='strict'):
|
|
self.encoding = encoding
|
|
"""Text encoding for the input source."""
|
|
|
|
self.error_handler = error_handler
|
|
"""Text decoding error handler."""
|
|
|
|
self.source = source
|
|
"""The source of input data."""
|
|
|
|
self.source_path = source_path
|
|
"""A text reference to the source."""
|
|
|
|
if not source_path:
|
|
self.source_path = self.default_source_path
|
|
|
|
self.successful_encoding = None
|
|
"""The encoding that successfully decoded the source data."""
|
|
|
|
def __repr__(self):
|
|
return '%s: source=%r, source_path=%r' % (self.__class__, self.source,
|
|
self.source_path)
|
|
|
|
def read(self):
|
|
raise NotImplementedError
|
|
|
|
def decode(self, data):
|
|
"""
|
|
Decode a string, `data`, heuristically.
|
|
Raise UnicodeError if unsuccessful.
|
|
|
|
The client application should call ``locale.setlocale`` at the
|
|
beginning of processing::
|
|
|
|
locale.setlocale(locale.LC_ALL, '')
|
|
"""
|
|
if self.encoding and self.encoding.lower() == 'unicode':
|
|
assert isinstance(data, str), (
|
|
'input encoding is "unicode" '
|
|
'but input is not a unicode object')
|
|
if isinstance(data, str):
|
|
# Accept unicode even if self.encoding != 'unicode'.
|
|
return data
|
|
if self.encoding:
|
|
# We believe the user/application when the encoding is
|
|
# explicitly given.
|
|
encodings = [self.encoding]
|
|
else:
|
|
data_encoding = self.determine_encoding_from_data(data)
|
|
if data_encoding:
|
|
# If the data declares its encoding (explicitly or via a BOM),
|
|
# we believe it.
|
|
encodings = [data_encoding]
|
|
else:
|
|
# Apply heuristics only if no encoding is explicitly given and
|
|
# no BOM found. Start with UTF-8, because that only matches
|
|
# data that *IS* UTF-8:
|
|
encodings = ['utf-8', 'latin-1']
|
|
if locale_encoding:
|
|
encodings.insert(1, locale_encoding)
|
|
for enc in encodings:
|
|
try:
|
|
decoded = str(data, enc, self.error_handler)
|
|
self.successful_encoding = enc
|
|
# Return decoded, removing BOMs.
|
|
return decoded.replace('\ufeff', '')
|
|
except (UnicodeError, LookupError) as err:
|
|
error = err # in Python 3, the <exception instance> is
|
|
# local to the except clause
|
|
raise UnicodeError(
|
|
'Unable to decode input data. Tried the following encodings: '
|
|
'%s.\n(%s)' % (', '.join([repr(enc) for enc in encodings]),
|
|
ErrorString(error)))
|
|
|
|
coding_slug = re.compile(br"coding[:=]\s*([-\w.]+)")
|
|
"""Encoding declaration pattern."""
|
|
|
|
byte_order_marks = ((codecs.BOM_UTF8, 'utf-8'),
|
|
(codecs.BOM_UTF16_BE, 'utf-16-be'),
|
|
(codecs.BOM_UTF16_LE, 'utf-16-le'),)
|
|
"""Sequence of (start_bytes, encoding) tuples for encoding detection.
|
|
The first bytes of input data are checked against the start_bytes strings.
|
|
A match indicates the given encoding."""
|
|
|
|
def determine_encoding_from_data(self, data):
|
|
"""
|
|
Try to determine the encoding of `data` by looking *in* `data`.
|
|
Check for a byte order mark (BOM) or an encoding declaration.
|
|
"""
|
|
# check for a byte order mark:
|
|
for start_bytes, encoding in self.byte_order_marks:
|
|
if data.startswith(start_bytes):
|
|
return encoding
|
|
# check for an encoding declaration pattern in first 2 lines of file:
|
|
for line in data.splitlines()[:2]:
|
|
match = self.coding_slug.search(line)
|
|
if match:
|
|
return match.group(1).decode('ascii')
|
|
return None
|
|
|
|
|
|
class Output(TransformSpec):
|
|
|
|
"""
|
|
Abstract base class for output wrappers.
|
|
"""
|
|
|
|
component_type = 'output'
|
|
|
|
default_destination_path = None
|
|
|
|
def __init__(self, destination=None, destination_path=None,
|
|
encoding=None, error_handler='strict'):
|
|
self.encoding = encoding
|
|
"""Text encoding for the output destination."""
|
|
|
|
self.error_handler = error_handler or 'strict'
|
|
"""Text encoding error handler."""
|
|
|
|
self.destination = destination
|
|
"""The destination for output data."""
|
|
|
|
self.destination_path = destination_path
|
|
"""A text reference to the destination."""
|
|
|
|
if not destination_path:
|
|
self.destination_path = self.default_destination_path
|
|
|
|
def __repr__(self):
|
|
return ('%s: destination=%r, destination_path=%r'
|
|
% (self.__class__, self.destination, self.destination_path))
|
|
|
|
def write(self, data):
|
|
"""`data` is a Unicode string, to be encoded by `self.encode`."""
|
|
raise NotImplementedError
|
|
|
|
def encode(self, data):
|
|
if self.encoding and self.encoding.lower() == 'unicode':
|
|
assert isinstance(data, str), (
|
|
'the encoding given is "unicode" but the output is not '
|
|
'a Unicode string')
|
|
return data
|
|
if not isinstance(data, str):
|
|
# Non-unicode (e.g. bytes) output.
|
|
return data
|
|
else:
|
|
return data.encode(self.encoding, self.error_handler)
|
|
|
|
|
|
class FileInput(Input):
|
|
|
|
"""
|
|
Input for single, simple file-like objects.
|
|
"""
|
|
def __init__(self, source=None, source_path=None,
|
|
encoding=None, error_handler='strict',
|
|
autoclose=True,
|
|
mode='r' if sys.version_info >= (3, 4) else 'rU', **kwargs):
|
|
"""
|
|
:Parameters:
|
|
- `source`: either a file-like object (which is read directly), or
|
|
`None` (which implies `sys.stdin` if no `source_path` given).
|
|
- `source_path`: a path to a file, which is opened and then read.
|
|
- `encoding`: the expected text encoding of the input file.
|
|
- `error_handler`: the encoding error handler to use.
|
|
- `autoclose`: close automatically after read (except when
|
|
`sys.stdin` is the source).
|
|
- `mode`: how the file is to be opened (see standard function
|
|
`open`). The default 'rU' provides universal newline support
|
|
for text files on Python < 3.4.
|
|
"""
|
|
Input.__init__(self, source, source_path, encoding, error_handler)
|
|
self.autoclose = autoclose
|
|
self._stderr = ErrorOutput()
|
|
# deprecation warning
|
|
for key in kwargs:
|
|
if key == 'handle_io_errors':
|
|
sys.stderr.write('deprecation warning: '
|
|
'io.FileInput() argument `handle_io_errors` '
|
|
'is ignored since Docutils 0.10 (2012-12-16) '
|
|
'and will soon be removed.')
|
|
else:
|
|
raise TypeError('__init__() got an unexpected keyword '
|
|
"argument '%s'" % key)
|
|
|
|
if source is None:
|
|
if source_path:
|
|
# Specify encoding in Python 3
|
|
if sys.version_info >= (3,0):
|
|
kwargs = {'encoding': self.encoding,
|
|
'errors': self.error_handler}
|
|
else:
|
|
kwargs = {}
|
|
|
|
try:
|
|
self.source = open(source_path, mode, **kwargs)
|
|
except IOError as error:
|
|
raise InputError(error.errno, error.strerror, source_path)
|
|
else:
|
|
self.source = sys.stdin
|
|
elif (sys.version_info >= (3,0) and
|
|
check_encoding(self.source, self.encoding) is False):
|
|
# TODO: re-open, warn or raise error?
|
|
raise UnicodeError('Encoding clash: encoding given is "%s" '
|
|
'but source is opened with encoding "%s".' %
|
|
(self.encoding, self.source.encoding))
|
|
if not source_path:
|
|
try:
|
|
self.source_path = self.source.name
|
|
except AttributeError:
|
|
pass
|
|
|
|
def read(self):
|
|
"""
|
|
Read and decode a single file and return the data (Unicode string).
|
|
"""
|
|
try:
|
|
if self.source is sys.stdin and sys.version_info >= (3,0):
|
|
# read as binary data to circumvent auto-decoding
|
|
data = self.source.buffer.read()
|
|
# normalize newlines
|
|
data = b'\n'.join(data.splitlines()) + b'\n'
|
|
else:
|
|
data = self.source.read()
|
|
except (UnicodeError, LookupError) as err: # (in Py3k read() decodes)
|
|
if not self.encoding and self.source_path:
|
|
# re-read in binary mode and decode with heuristics
|
|
b_source = open(self.source_path, 'rb')
|
|
data = b_source.read()
|
|
b_source.close()
|
|
# normalize newlines
|
|
data = b'\n'.join(data.splitlines()) + b'\n'
|
|
else:
|
|
raise
|
|
finally:
|
|
if self.autoclose:
|
|
self.close()
|
|
return self.decode(data)
|
|
|
|
def readlines(self):
|
|
"""
|
|
Return lines of a single file as list of Unicode strings.
|
|
"""
|
|
return self.read().splitlines(True)
|
|
|
|
def close(self):
|
|
if self.source is not sys.stdin:
|
|
self.source.close()
|
|
|
|
|
|
class FileOutput(Output):
|
|
|
|
"""
|
|
Output for single, simple file-like objects.
|
|
"""
|
|
|
|
mode = 'w'
|
|
"""The mode argument for `open()`."""
|
|
# 'wb' for binary (e.g. OpenOffice) files (see also `BinaryFileOutput`).
|
|
# (Do not use binary mode ('wb') for text files, as this prevents the
|
|
# conversion of newlines to the system specific default.)
|
|
|
|
def __init__(self, destination=None, destination_path=None,
|
|
encoding=None, error_handler='strict', autoclose=True,
|
|
handle_io_errors=None, mode=None):
|
|
"""
|
|
:Parameters:
|
|
- `destination`: either a file-like object (which is written
|
|
directly) or `None` (which implies `sys.stdout` if no
|
|
`destination_path` given).
|
|
- `destination_path`: a path to a file, which is opened and then
|
|
written.
|
|
- `encoding`: the text encoding of the output file.
|
|
- `error_handler`: the encoding error handler to use.
|
|
- `autoclose`: close automatically after write (except when
|
|
`sys.stdout` or `sys.stderr` is the destination).
|
|
- `handle_io_errors`: ignored, deprecated, will be removed.
|
|
- `mode`: how the file is to be opened (see standard function
|
|
`open`). The default is 'w', providing universal newline
|
|
support for text files.
|
|
"""
|
|
Output.__init__(self, destination, destination_path,
|
|
encoding, error_handler)
|
|
self.opened = True
|
|
self.autoclose = autoclose
|
|
if mode is not None:
|
|
self.mode = mode
|
|
self._stderr = ErrorOutput()
|
|
if destination is None:
|
|
if destination_path:
|
|
self.opened = False
|
|
else:
|
|
self.destination = sys.stdout
|
|
elif (# destination is file-type object -> check mode:
|
|
mode and hasattr(self.destination, 'mode')
|
|
and mode != self.destination.mode):
|
|
print(('Warning: Destination mode "%s" '
|
|
'differs from specified mode "%s"' %
|
|
(self.destination.mode, mode)), file=self._stderr)
|
|
if not destination_path:
|
|
try:
|
|
self.destination_path = self.destination.name
|
|
except AttributeError:
|
|
pass
|
|
|
|
def open(self):
|
|
# Specify encoding in Python 3.
|
|
if sys.version_info >= (3,0) and 'b' not in self.mode:
|
|
kwargs = {'encoding': self.encoding,
|
|
'errors': self.error_handler}
|
|
else:
|
|
kwargs = {}
|
|
try:
|
|
self.destination = open(self.destination_path, self.mode, **kwargs)
|
|
except IOError as error:
|
|
raise OutputError(error.errno, error.strerror,
|
|
self.destination_path)
|
|
self.opened = True
|
|
|
|
def write(self, data):
|
|
"""Encode `data`, write it to a single file, and return it.
|
|
|
|
With Python 3 or binary output mode, `data` is returned unchanged,
|
|
except when specified encoding and output encoding differ.
|
|
"""
|
|
if not self.opened:
|
|
self.open()
|
|
if ('b' not in self.mode and sys.version_info < (3,0)
|
|
or check_encoding(self.destination, self.encoding) is False
|
|
):
|
|
data = self.encode(data)
|
|
if sys.version_info >= (3,0) and os.linesep != '\n':
|
|
data = data.replace(b'\n', bytes(os.linesep, 'ascii')) # fix endings
|
|
|
|
try:
|
|
self.destination.write(data)
|
|
except TypeError as e:
|
|
if sys.version_info >= (3,0) and isinstance(data, bytes):
|
|
try:
|
|
self.destination.buffer.write(data)
|
|
except AttributeError:
|
|
if check_encoding(self.destination,
|
|
self.encoding) is False:
|
|
raise ValueError('Encoding of %s (%s) differs \n'
|
|
' from specified encoding (%s)' %
|
|
(self.destination_path or 'destination',
|
|
self.destination.encoding, self.encoding))
|
|
else:
|
|
raise e
|
|
except (UnicodeError, LookupError) as err:
|
|
raise UnicodeError(
|
|
'Unable to encode output data. output-encoding is: '
|
|
'%s.\n(%s)' % (self.encoding, ErrorString(err)))
|
|
finally:
|
|
if self.autoclose:
|
|
self.close()
|
|
return data
|
|
|
|
def close(self):
|
|
if self.destination not in (sys.stdout, sys.stderr):
|
|
self.destination.close()
|
|
self.opened = False
|
|
|
|
|
|
class BinaryFileOutput(FileOutput):
|
|
"""
|
|
A version of docutils.io.FileOutput which writes to a binary file.
|
|
"""
|
|
# Used by core.publish_cmdline_to_binary() which in turn is used by
|
|
# rst2odt (OpenOffice writer)
|
|
mode = 'wb'
|
|
|
|
|
|
class StringInput(Input):
|
|
|
|
"""
|
|
Direct string input.
|
|
"""
|
|
|
|
default_source_path = '<string>'
|
|
|
|
def read(self):
|
|
"""Decode and return the source string."""
|
|
return self.decode(self.source)
|
|
|
|
|
|
class StringOutput(Output):
|
|
|
|
"""
|
|
Direct string output.
|
|
"""
|
|
|
|
default_destination_path = '<string>'
|
|
|
|
def write(self, data):
|
|
"""Encode `data`, store it in `self.destination`, and return it."""
|
|
self.destination = self.encode(data)
|
|
return self.destination
|
|
|
|
|
|
class NullInput(Input):
|
|
|
|
"""
|
|
Degenerate input: read nothing.
|
|
"""
|
|
|
|
default_source_path = 'null input'
|
|
|
|
def read(self):
|
|
"""Return a null string."""
|
|
return ''
|
|
|
|
|
|
class NullOutput(Output):
|
|
|
|
"""
|
|
Degenerate output: write nothing.
|
|
"""
|
|
|
|
default_destination_path = 'null output'
|
|
|
|
def write(self, data):
|
|
"""Do nothing ([don't even] send data to the bit bucket)."""
|
|
pass
|
|
|
|
|
|
class DocTreeInput(Input):
|
|
|
|
"""
|
|
Adapter for document tree input.
|
|
|
|
The document tree must be passed in the ``source`` parameter.
|
|
"""
|
|
|
|
default_source_path = 'doctree input'
|
|
|
|
def read(self):
|
|
"""Return the document tree."""
|
|
return self.source
|