Set permnission with makedirs

[Gribouillis]

I try the same on my computer and it works

Output:
λ python
Python 3.10.6 (main, May 29 2023, 11:10:38) [GCC 11.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from os import makedirs
>>> makedirs('somewhere', mode=0o0755)
>>> 
λ stat somewhere
  File: somewhere
  Size: 4096            Blocks: 8          IO Block: 4096   directory
Device: 804h/2052d      Inode: 19141748    Links: 2
Access: (0755/drwxr-xr-x)  Uid: ( 1000/    eric)   Gid: ( 1000/    eric)
Access: 2023-06-06 14:47:15.152311228 +0200
Modify: 2023-06-06 14:47:15.152311228 +0200
Change: 2023-06-06 14:47:15.152311228 +0200
 Birth: 2023-06-06 14:47:15.152311228 +0200
λ  rmdir somewhere
λ 

The only difference is that I created somewhere and not /somewhere. Are you doing this as super-user?