seek¶

Description¶

Sets the file’s current position.

Syntax¶

file. seek(offset[, whence])

offset: Required. The offset from the beginning of the file.
whence: Optional. The whence argument is optional and defaults to os.SEEK_SET or 0 (absolute file positioning); other values are os.SEEK_CUR or 1 (seek relative to the current position) and os.SEEK_END or 2 (seek relative to the file’s end). There is no return value.

Remarks¶

Note that if the file is opened for appending (mode ‘a’ or ‘a+’), any seek() operations will be undone at the next write. If the file is only opened for writing in append mode (mode ‘a’), this method is essentially a no-op, but it remains useful for files opened in append mode with reading enabled (mode ‘a+’). If the file is opened in text mode (without ‘b’), only offsets returned by tell() are legal. Use of other offsets causes undefined behavior.

Note that not all file objects are seekable.

Changed in version 2.6: Passing float values as offset has been deprecated.

Return Value¶

None

Time Complexity¶

#TODO

Example 1¶

>>> # test.txt contents:
>>> # ABCDE
>>> f = open(r'C:\test.txt')
>>> f.seek(3)
>>> f.read()   # starts reading from the 3rd character
'DE'

Example 2¶

>>> f = open(r'C:\test.txt')
>>> f.seek(2)    # move two characters ahead
>>> f.seek(2, 1) # move two characters ahead from the current position
>>> f.read()
'E'

Example 3¶

>>> f = open(r'C:\test.txt')
>>> f.seek(-3, 2) # move to the 3rd character from the end of the file
>>> f.read()
'CDE'