Why doesn't the clean-up persist?

Question

I clean a csv table. I want to delete symbols in the ID. It looks like this:

ID    Address
"(2   Hamburg
"(3   Cologne
"(4   Berlin
"(5   ...

I want to delete the "(

The code I used

Ost.applymap(lambda x: x.replace('"(', ''))

when I check the csv file after saving, the deleted symbols are back. Like nothing changed. Why is the change not saving?

Answer 1

You need to reassign the change to the variable:

Ost = Ost.applymap(lambda x: x.replace('"(', ''))

The output of:

Ost.applymap(lambda x: x.replace('"(', ''))
Ost

is

    ID    Address
0    (2   Hamburg
1    (3   Cologne
2    (4   Berlin

As you can see it isn't applymap isn't make the change inplace