# Split a column in Pandas dataframe and get part of it in Python 
 import pandas as pd
import numpy as np
df = pd.DataFrame({'Geek_ID':['Geek1_id', 'Geek2_id', 'Geek3_id', 
                                         'Geek4_id', 'Geek5_id'],
                'Geek_A': [1, 1, 3, 2, 4],
                'Geek_B': [1, 2, 3, 4, 6],
                'Geek_R': np.random.randn(5)})
  
# Geek_A  Geek_B   Geek_ID    Geek_R
# 0       1       1  Geek1_id    random number
# 1       1       2  Geek2_id    random number
# 2       3       3  Geek3_id    random number
# 3       2       4  Geek4_id    random number
# 4       4       6  Geek5_id    random number
  
print(df.Geek_ID.str.split('_').str[0])