df = pd.DataFrame([[1, 2], [3, 4]], columns=list(‘AB‘))
df2 = pd.DataFrame([[5, 6], [7, 8]], columns=list(‘AB‘))
c=pd.concat([df,df2],ignore_index=False)
print c 

df = pd.DataFrame([[1, 2], [3, 4]], columns=list(‘AB‘))
df2 = pd.DataFrame([[5, 6], [7, 8]], columns=list(‘AB‘))
c=pd.concat([df,df2],ignore_index=True)
print c 

1 df = pd.DataFrame([[1, 2], [3, 4]], columns=list(‘AB‘))
2 df2 = pd.DataFrame([[5, 6], [7, 8]], columns=list(‘AB‘))
3 w=df.append(df2)
4 print w