remove prefix in all column names

Question

I would like to remove the prefix from all column names in a dataframe.

I tried creating a udf and calling it in a for loop

def remove_prefix(str, prefix):
    if str.startswith(blabla):
        return str[len(prefix):]
    return str

for x in df.columns:
    x.remove_prefix()

Answer 1

Use Series.str.replace with regex ^ for match start of string:

df = pd.DataFrame(columns=['pre_A', 'pre_B', 'pre_predmet'])
df.columns = df.columns.str.replace('^pre_', '')
print (df)
Empty DataFrame
Columns: [A, B, predmet]
Index: []

Another solution is use list comprehension with re.sub:

import re

df.columns = [re.sub('^pre_',"", x) for x in df.columns]