rename_columns_regex

# import libraries
import re
import pandas as pd
import numpy as np

# create a dataframe
df = pd.DataFrame({"columnA1": np.linspace(0, 10, num=10),
                   "columnB20": np.linspace(10, 20, num=10),
                   "columnC305": np.linspace(20, 30, num=10)}
                  )

# view dataframe columns names
print(df.columns)

# create replacement column names without trailing numbers
new_cols = (re.sub(r"\d*$", "", col) for col in df.columns)
rename_cols = dict(zip(df.columns, new_cols))

# rename columns
df = df.rename(columns=rename_cols)
print(df.columns)