how to merge two data frames based on particular column in pandas python?

Question

I have to merge two dataframes:

df1

company,standard
tata,A1
cts,A2
dell,A3

df2

company,return
tata,71
dell,78
cts,27
hcl,23

I have to unify both dataframes to one dataframe. I need output like:

company,standard,return
tata,A1,71
cts,A2,27
dell,A3,78

Answer 1

Use merge:

print (pd.merge(df1, df2, on='company'))

Sample:

print (df1)
  company standard
0    tata       A1
1     cts       A2
2    dell       A3

print (df2)
  company  return
0    tata      71
1    dell      78
2     cts      27
3     hcl      23

print (pd.merge(df1, df2, on='company'))
  company standard  return
0    tata       A1      71
1     cts       A2      27
2    dell       A3      78

Answer 2

I think we can also use

df1.merge(df2,on='Company')

Answer 3

In order to successfully merge two data frames based on common column(s), the dtype for common column(s) in both data frames must be the same! dtype for a column can be changed by:

df['commonCol'] = df['commonCol'].astype(int)