import pandas as pd
final_df_merged = pd.read_csv('final_merged_en.csv')
/srv/paws/lib/python3.6/site-packages/IPython/core/interactiveshell.py:2785: DtypeWarning: Columns (8,9,16) have mixed types. Specify dtype option on import or set low_memory=False.
  interactivity=interactivity, compiler=compiler, result=result)
final_df_merged =final_df_merged.drop(columns=['Unnamed: 0']) 
revision2 = pd.read_csv('en_revisions2.csv')
revision2 = revision2.drop(columns=['Unnamed: 0']) 
revision1 = pd.read_csv('en_revisions1.csv')
revision1 = revision1.drop(columns=['Unnamed: 0']) 
revision3 = pd.read_csv('en_revisions3.csv')
revision3 = revision3.drop(columns=['Unnamed: 0']) 
revisions = pd.concat([revision1, revision2,revision3])
to_be_saved = pd.merge(final_df_merged, revisions, how='left', on='en_page_id')
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-1-8def7b771739> in <module>()
----> 1 to_be_saved = pd.merge(final_df_merged, revisions, how='left', on='en_page_id')

NameError: name 'pd' is not defined