pythone IO.py 文件源代码

#io 模块主要是提供了用于处理数据流的核心工具
'''
数据流：
    文本数据流 txt i/o
    二进制数据流 binary io
    原始数据流 raw io
'''
#创建文本流的方式
#方式1
import io
f = io.StringIO("some initial text data")
f.close()
#方式2
f=open("a.txt","r",encoding="utf-8")
#16.2.1.2. Binary I/O (also called *buffered I/O*)
'''
The easiest way to create a binary stream is with "open()" with "'b'"
in the mode string:
'''
f = open("myfile.jpg", "rb")
#  In-memory binary streams are also available as "BytesIO" objects:
f = io.BytesIO(b"some initial binary data: \x00\x01")

## 16.2.1.3. Raw I/O
#禁用无无缓冲io流的方式
f = open("myfile.jpg", "rb", buffering=0)
# High-level Module Interface  高级模块接口
"""
io.DEFAULT_BUFFER_SIZE

   An int containing the default buffer size used by the module's
   buffered I/O classes.  "open()" uses the file's blksize (as
   obtained by "os.stat()") if possible.
   包含模块缓冲I / O类使用的默认缓冲区大小的int。 如果可能，“open（）”使用文件的blksize（由“os.stat（）”获得）。
"""
print(io.DEFAULT_BUFFER_SIZE) #默认二进制文件的流的大小8192

io.open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

   This is an alias for the builtin "open()" function.
'''
16.2.2.1. In-memory streams 内存数据流
It is also possible to use a "str" or *bytes-like object* as a file
for both reading and writing.  For strings "StringIO" can be used like
a file opened in text mode.  "BytesIO" can be used like a file opened
in binary mode.  Both provide full read-write capabilities with random
access.

See also:

  "sys"
     contains the standard IO streams: "sys.stdin", "sys.stdout", and
     "sys.stderr".
'''