Python Forum

Hello, can someone please explain why when I select a range starting from the end of a string it truncates the last character?
I can work from the front end as variable dst will always be the same length but when faced with an unknown string length it would be an issue

dst = (r"C:\Users\tekno\Documents\Client Drawings\AAA001")
dwg_name = (dst[-7:-1])
print(dst)
print(dwg_name)
print(dst[40:47])
print(dst[-7:-1])
print(dst[-1])

Output:
C:\Users\tekno\Documents\Client Drawings\AAA001
\AAA00
\AAA001
\AAA00
1

Why the parenthesis in the first two lines? They do nothing.

Slices work just like the for loop. They start at the start and end just before the end. To slice all the way to the end don't specify an end.

dwg_name = dst[-7:]

Same goes for slicing from the start.

dwg_name = dst[:7]

Rather than [-7:-1] to go to the end [-7:] -7 and the rest.

dst = (r"C:\Users\tekno\Documents\Client Drawings\AAA001")
dwg_name = dst[-7:]
print(dst)
print(dwg_name)

Output:
C:\Users\tekno\Documents\Client Drawings\AAA001
\AAA001

Use pathlib then it become much more flexible.

>>> import pathlib
>>> 
>>> dst = r"C:\Users\tekno\Documents\Client Drawings\AAA001"
>>> folder_last = pathlib.PurePath(dst).name
>>> folder_last
'AAA001'
>>> 
>>> # Join would be
>>> my_path = pathlib.Path('C:\\')
>>> my_path.joinpath(folder_last)
WindowsPath('C:/AAA001')
>>> pathlib.Path.home().joinpath(folder_last)
WindowsPath('C:/Users/Tom/AAA001')