文件的操作

  1 class file(object):
  2   
  3     def close(self): # real signature unknown; restored from __doc__
  4         关闭文件
  5         """
  6         close() -> None or (perhaps) an integer.  Close the file.
  7          
  8         Sets data attribute .closed to True.  A closed file cannot be used for
  9         further I/O operations.  close() may be called more than once without
 10         error.  Some kinds of file objects (for example, opened by popen())
 11         may return an exit status upon closing.
 12         """
 13  
 14     def fileno(self): # real signature unknown; restored from __doc__
 15         文件描述符  
 16          """
 17         fileno() -> integer "file descriptor".
 18          
 19         This is needed for lower-level file interfaces, such os.read().
 20         """
 21         return 0    
 22  
 23     def flush(self): # real signature unknown; restored from __doc__
 24         刷新文件内部缓冲区
 25         """ flush() -> None.  Flush the internal I/O buffer. """
 26         pass
 27  
 28  
 29     def isatty(self): # real signature unknown; restored from __doc__
 30         判断文件是否是同意tty设备
 31         """ isatty() -> true or false.  True if the file is connected to a tty device. """
 32         return False
 33  
 34  
 35     def next(self): # real signature unknown; restored from __doc__
 36         获取下一行数据，不存在，则报错
 37         """ x.next() -> the next value, or raise StopIteration """
 38         pass
 39  
 40     def read(self, size=None): # real signature unknown; restored from __doc__
 41         读取指定字节数据
 42         """
 43         read([size]) -> read at most size bytes, returned as a string.
 44          
 45         If the size argument is negative or omitted, read until EOF is reached.
 46         Notice that when in non-blocking mode, less data than what was requested
 47         may be returned, even if no size parameter was given.
 48         """
 49         pass
 50  
 51     def readinto(self): # real signature unknown; restored from __doc__
 52         读取到缓冲区，不要用，将被遗弃
 53         """ readinto() -> Undocumented.  Don't use this; it may go away. """
 54         pass
 55  
 56     def readline(self, size=None): # real signature unknown; restored from __doc__
 57         仅读取一行数据
 58         """
 59         readline([size]) -> next line from the file, as a string.
 60          
 61         Retain newline.  A non-negative size argument limits the maximum
 62         number of bytes to return (an incomplete line may be returned then).
 63         Return an empty string at EOF.
 64         """
 65         pass
 66  
 67     def readlines(self, size=None): # real signature unknown; restored from __doc__
 68         读取所有数据，并根据换行保存值列表
 69         """
 70         readlines([size]) -> list of strings, each a line from the file.
 71          
 72         Call readline() repeatedly and return a list of the lines so read.
 73         The optional size argument, if given, is an approximate bound on the
 74         total number of bytes in the lines returned.
 75         """
 76         return []
 77  
 78     def seek(self, offset, whence=None): # real signature unknown; restored from __doc__
 79         指定文件中指针位置
 80         """
 81         seek(offset[, whence]) -> None.  Move to new file position.
 82          
 83         Argument offset is a byte count.  Optional argument whence defaults to
 84         0 (offset from start of file, offset should be >= 0); other values are 1
 85         (move relative to current position, positive or negative), and 2 (move
 86         relative to end of file, usually negative, although many platforms allow
 87         seeking beyond the end of a file).  If the file is opened in text mode,
 88         only offsets returned by tell() are legal.  Use of other offsets causes
 89         undefined behavior.
 90         Note that not all file objects are seekable.
 91         """
 92         pass
 93  
 94     def tell(self): # real signature unknown; restored from __doc__
 95         获取当前指针位置
 96         """ tell() -> current file position, an integer (may be a long integer). """
 97         pass
 98  
 99     def truncate(self, size=None): # real signature unknown; restored from __doc__
100         截断数据，仅保留指定之前数据
101         """
102         truncate([size]) -> None.  Truncate the file to at most size bytes.
103          
104         Size defaults to the current file position, as returned by tell().
105         """
106         pass
107  
108     def write(self, p_str): # real signature unknown; restored from __doc__
109         写内容
110         """
111         write(str) -> None.  Write string str to file.
112          
113         Note that due to buffering, flush() or close() may be needed before
114         the file on disk reflects the data written.
115         """
116         pass
117  
118     def writelines(self, sequence_of_strings): # real signature unknown; restored from __doc__
119         将一个字符串列表写入文件
120         """
121         writelines(sequence_of_strings) -> None.  Write the strings to the file.
122          
123         Note that newlines are not added.  The sequence can be any iterable object
124         producing strings. This is equivalent to calling write() for each string.
125         """
126         pass
127  
128     def xreadlines(self): # real signature unknown; restored from __doc__
129         可用于逐行读取文件，非全部
130         """
131         xreadlines() -> returns self.
132          
133         For backward compatibility. File objects now include the performance
134         optimizations previously implemented in the xreadlines module.
135         """
136         pass