Sep-27-2019, 09:04 AM
(This post was last modified: Sep-27-2019, 09:04 AM by jollydragon.)
offset can not be negative in File.seek()?
offset can not be negative in File.seek()?
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Sep-27-2019, 11:46 AM
What is
csv_file ?
With the right whence-flag, you can use negative numbers.
Look here: https://docs.python.org/3/library/io.htm...OBase.seek In [1]: from pathlib import Path In [2]: raspbian = Path('Downloads/2019-07-10-raspbian-buster-lite.zip') In [3]: with raspbian.open('rb') as fd: ...: print('Size:', raspbian.stat().st_size) ...: print('Pos:', fd.tell()) ...: print('Seek to -10 bytes from end') ...: fd.seek(-10, 2) ...: print('New position:', fd.tell()) ...: Size: 426250971 Pos: 0 Seek to -10 bytes from end New position: 426250961Instead of recognizing the number for 'whence', you can use os.SEEK_END: In [10]: print(os.SEEK_SET, os.SEEK_CUR, os.SEEK_END) 0 1 2 In addition, I've used pathlib.Path, which is better to handle. You can still use the built-in function open() .The resulting file-object is the same as from Path.open(mode) .
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Sep-27-2019, 01:35 PM
(This post was last modified: Sep-27-2019, 01:35 PM by jollydragon.)
Sep-27-2019, 07:01 PM
The negative seek works if the file is opened in binary mode 'rb'.
Sep-28-2019, 12:05 AM
Sep-28-2019, 03:08 AM
(This post was last modified: Sep-28-2019, 03:08 AM by jollydragon.)
Found the explaination on internet, and thank you again.
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