『壹』 python3 有多少內置函數
我剛剛數了下Python3.x一共有153個內置函數
具體如下：
['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning', 'ChildProcessError', 'ConnectionAbortedError', 'ConnectionError', 'ConnectionRefusedError', 'ConnectionResetError', 'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False', 'FileExistsError', 'FileNotFoundError', 'FloatingPointError', 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', 'ImportWarning', 'IndentationError', 'IndexError', 'InterruptedError', 'IsADirectoryError', 'KeyError', 'KeyboardInterrupt', 'LookupError', 'MemoryError', 'MoleNotFoundError', 'NameError', 'None', 'NotADirectoryError', 'NotImplemented', 'NotImplementedError', 'OSError', 'OverflowError', 'PendingDeprecationWarning', 'PermissionError', 'ProcessLookupError', 'RecursionError', 'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning', 'StopAsyncIteration', 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError', 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning', 'ValueError', 'Warning', 'WindowsError', 'ZeroDivisionError', '_', '__build_class__', '__debug__', '__doc__', '__import__', '__loader__', '__name__', '__package__', '__spec__', 'abs', 'all', 'any', 'ascii', 'bin', 'bool', 'bytearray', 'bytes', 'callable', 'chr', 'classmethod', 'compile', 'complex', 'right', 'credits', 'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', 'exec', 'exit', 'filter', 'float', 'format', 'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', 'input', 'int', 'isinstance', 'issubclass', 'iter', 'len', 'license', 'list', 'locals', 'map', 'max', 'memoryview', 'min', 'next', 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip']
『貳』 如何在python中使用protocol buffer
先安裝protobuf的編譯器軟體
然後編寫自己的描述文件（.proto）
然後運行
protoc -I=$SRC_DIR --python_out=$DST_DIR $SRC_DIR/YOUR.proto
會得到python的YOUR_pb2.py庫文件
丟到項目裡面導入然後使用即可
『叄』 python出錯：expected a character buffer object
TypeError: expected a character buffer object
應該是參數類型錯誤，具體的你要看一下報錯的具體位置：會在報錯信息裡面
你以後提問題，一定要把錯誤信息完整的截圖出來；或者你把源代碼貼出來，而不是放幾張截圖。
『肆』 python中的 open函數參數 buffer是什麼意思
:有目錄就有簽到，你可以到後台提交貼吧目錄，每周提交2次，至於速度這個不保證，你也可以後台提交目錄後，再到貼吧分類吧申請目錄。等你的貼吧有目錄後，第二天就會有簽到了注意：申請目錄必須是那吧的吧主才行。
『伍』 python sys.stdout.buffer.write什麼意思
sys是系統 stdout是標准輸出 buffer是緩沖區 write是寫 往標准輸出的緩沖區中寫東西
『陸』 如何使用Python中的buffer
1.需要安裝Protocol Buffer
直接：apt-get install protobuf-compiler
安裝完畢後，進入解壓目錄的Python目錄，執行python setup.py install；安裝python的protobuf庫即可。
2.可以查詢到它的大致用法
pijing@ubuntu:~/protobuffer$ protoc -h
Usage: protoc [OPTION] PROTO_FILES
Parse PROTO_FILES and generate output based on the options given:
-IPATH, --proto_path=PATH Specify the directory in which to search for
imports. May be specified multiple times;
directories will be searched in order. If not
given, the current working directory is used.
--version Show version info and exit.
-h, --help Show this text and exit.
--encode=MESSAGE_TYPE Read a text-format message of the given type
from standard input and write it in binary
to standard output. The message type must
be defined in PROTO_FILES or their imports.
--decode=MESSAGE_TYPE Read a binary message of the given type from
standard input and write it in text format
to standard output. The message type must
be defined in PROTO_FILES or their imports.
--decode_raw Read an arbitrary protocol message from
standard input and write the raw tag/value
pairs in text format to standard output. No
PROTO_FILES should be given when using this
flag.
-oFILE, Writes a FileDescriptorSet (a protocol buffer,
--descriptor_set_out=FILE defined in descriptor.proto) containing all of
the input files to FILE.
--include_imports When using --descriptor_set_out, also include
all dependencies of the input files in the
set, so that the set is self-contained.
--include_source_info When using --descriptor_set_out, do not strip
SourceCodeInfo from the FileDescriptorProto.
This results in vastly larger descriptors that
include information about the original
location of each decl in the source file as
well as surrounding comments.
--error_format=FORMAT Set the format in which to print errors.
FORMAT may be 'gcc' (the default) or 'msvs'
(Microsoft Visual Studio format).
--plugin=EXECUTABLE Specifies a plugin executable to use.
Normally, protoc searches the PATH for
plugins, but you may specify additional
executables not in the path using this flag.
Additionally, EXECUTABLE may be of the form
NAME=PATH, in which case the given plugin name
is mapped to the given executable even if
the executable's own name differs.
--cpp_out=OUT_DIR Generate C++ header and source.
--java_out=OUT_DIR Generate Java source file.
--python_out=OUT_DIR Generate Python source file.
3.簡單使用一下
首先定義proto文件，my.proto
{
optional int32 id=1;
optional string testname=2;
}
然後，執行命令：
protoc --python_out=./ ./my.proto
得到my_pb2.py文件
最後，在當前目錄下新建一個test.py文件夾，寫入測試的腳本，包括序列化和反序列化代碼：
『柒』 如何為python中的套接字設置發送緩沖區大小
使用socket.setsockopt()和SO_SNDBUF:
socket.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, <value>)
<value>是要設置為Python的緩沖區大小。int。
socket.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 8192) # Buffer size 8192