open(...)
open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None) -> file object
Open file and return a stream. Raise IOError upon failure.
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Character Meaning
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'r' open for reading (default)
'w' open for writing, truncating the file first
'x' create a new file and open it for writing
'a' open for writing, appending to the end of the file if it exists
'b' binary mode
't' text mode (default)
'+' open a disk file for updating (reading and writing)
'U' universal newline mode (deprecated)
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The default mode is 'rt' (open for reading text). For binary random access, the mode 'w+b' opens and truncates the file to 0 bytes, while 'r+b' opens the file without truncation.
The 'x' mode implies 'w' and raises an `FileExistsError` if the file already exists.
文件的打开模式：
文件的对象方法：
