Python's built-in file objects are implemented entirely on the FILE* support from the C standard library. This is an implementation detail and may change in future releases of Python.
types.FileType.
  
| PyObject *p) | 
| PyObject *p) | 
| char *filename, char *mode) | 
| FILE *fp, char *name, char *mode, int (*close)(FILE*)) | 
| PyFileObject *p) | 
| PyObject *p, int n) | 
p.readline([n]), this
  function reads one line from the object p.  p may be a
  file object or any object with a readline() method.  If
  n is 0, exactly one line is read, regardless of the
  length of the line.  If n is greater than 0, no more
  than n bytes will be read from the file; a partial line can be
  returned.  In both cases, an empty string is returned if the end of
  the file is reached immediately.  If n is less than 0,
  however, one line is read regardless of length, but
  EOFError is raised if the end of the file is reached
  immediately.
  
| PyObject *p) | 
| PyFileObject *p, int n) | 
| PyFileObject *p, char *enc) | 
| PyObject *p, int newflag) | 
0 as the previous
  value if the attribute either does not exist or if there were errors
  in retrieving it.  There is no way to detect errors from this
  function, but doing so should not be needed.
| PyObject *obj, PyFileObject *p, int flags) | 
0 on success or -1 on
  failure; the appropriate exception will be set.
| const char *s, PyFileObject *p) | 
0 on
  success or -1 on failure; the appropriate exception will be
  set.
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