def read_chunks(file, size=io.DEFAULT_BUFFER_SIZE):
"""Yield pieces of data from a file-like object until EOF."""
while True:
chunk = file.read(size)
if not chunk:
break
yield chunk
python类DEFAULT_BUFFER_SIZE的实例源码
def test_base64io_decode_readline(bytes_to_read, expected_bytes_read):
source_plaintext = os.urandom(io.DEFAULT_BUFFER_SIZE * 2)
source_stream = io.BytesIO(base64.b64encode(source_plaintext))
with Base64IO(source_stream) as decoder:
test = decoder.readline(bytes_to_read)
assert test == source_plaintext[:expected_bytes_read]
def readline(self, limit=-1):
# type: (int) -> bytes
"""Read and return one line from the stream.
If limit is specified, at most limit bytes will be read.
.. note::
Because the source that this reads from may not contain any OEL characters, we
read "lines" in chunks of length ``io.DEFAULT_BUFFER_SIZE``.
:type limit: int
:rtype: bytes
"""
return self.read(limit if limit > 0 else io.DEFAULT_BUFFER_SIZE)
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def read_chunks(file, size=io.DEFAULT_BUFFER_SIZE):
"""Yield pieces of data from a file-like object until EOF."""
while True:
chunk = file.read(size)
if not chunk:
break
yield chunk
def read_chunks(file, size=io.DEFAULT_BUFFER_SIZE):
"""Yield pieces of data from a file-like object until EOF."""
while True:
chunk = file.read(size)
if not chunk:
break
yield chunk
def readall(self):
"""Read until EOF, using multiple read() call."""
res = bytearray()
while True:
data = self.read(DEFAULT_BUFFER_SIZE)
if not data:
break
res += data
if res:
return bytes(res)
else:
# b'' or None
return data
def __init__(self, raw, buffer_size=DEFAULT_BUFFER_SIZE):
"""Create a new buffered reader using the given readable raw IO object.
"""
if not raw.readable():
raise IOError('"raw" argument must be readable.')
_BufferedIOMixin.__init__(self, raw)
if buffer_size <= 0:
raise ValueError("invalid buffer size")
self.buffer_size = buffer_size
self._reset_read_buf()
self._read_lock = Lock()
def __init__(self, raw,
buffer_size=DEFAULT_BUFFER_SIZE, max_buffer_size=None):
if not raw.writable():
raise IOError('"raw" argument must be writable.')
_BufferedIOMixin.__init__(self, raw)
if buffer_size <= 0:
raise ValueError("invalid buffer size")
if max_buffer_size is not None:
warnings.warn("max_buffer_size is deprecated", DeprecationWarning,
self._warning_stack_offset)
self.buffer_size = buffer_size
self._write_buf = bytearray()
self._write_lock = Lock()
def read_chunks(file, size=io.DEFAULT_BUFFER_SIZE):
"""Yield pieces of data from a file-like object until EOF."""
while True:
chunk = file.read(size)
if not chunk:
break
yield chunk
def read_chunks(file, size=io.DEFAULT_BUFFER_SIZE):
"""Yield pieces of data from a file-like object until EOF."""
while True:
chunk = file.read(size)
if not chunk:
break
yield chunk
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def read_chunks(file, size=io.DEFAULT_BUFFER_SIZE):
"""Yield pieces of data from a file-like object until EOF."""
while True:
chunk = file.read(size)
if not chunk:
break
yield chunk
def test_file_position_after_tofile(self):
# gh-4118
sizes = [io.DEFAULT_BUFFER_SIZE//8,
io.DEFAULT_BUFFER_SIZE,
io.DEFAULT_BUFFER_SIZE*8]
for size in sizes:
err_msg = "%d" % (size,)
f = open(self.filename, 'wb')
f.seek(size-1)
f.write(b'\0')
f.seek(10)
f.write(b'12')
np.array([0], dtype=np.float64).tofile(f)
pos = f.tell()
f.close()
assert_equal(pos, 10 + 2 + 8, err_msg=err_msg)
f = open(self.filename, 'r+b')
f.read(2)
f.seek(0, 1) # seek between read&write required by ANSI C
np.array([0], dtype=np.float64).tofile(f)
pos = f.tell()
f.close()
assert_equal(pos, 10, err_msg=err_msg)
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def backport_makefile(self, mode="r", buffering=None, encoding=None,
errors=None, newline=None):
"""
Backport of ``socket.makefile`` from Python 3.5.
"""
if not set(mode) <= set(["r", "w", "b"]):
raise ValueError(
"invalid mode %r (only r, w, b allowed)" % (mode,)
)
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = SocketIO(self, rawmode)
self._makefile_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
