add one column from one dataframe to another code example
Example 1: append one column pandas dataframe
df1 = df1.join(df2[column])
Example 2: Adding a new column in pandas dataframe from another dataframe with different index
merge(left, right, how='left', on=None, left_on=None, right_on=None,
left_index=False, right_index=False, sort=True,
suffixes=('_x', '_y'), copy=True)