combine two columns in pandas code example

Example 1: combining 2 dataframes pandas

df_3 = pd.concat([df_1, df_2])

Example 2: pandas merge two columns from different dataframes

#suppose you have two dataframes df1 and df2, and 
#you need to merge them along the column id
df_merge_col = pd.merge(df1, df2, on='id')

Example 3: add two column values of a datframe into one

df["period"] = df["Year"] + df["quarter"]

Example 4: how to merge two pandas dataframes on a column

import pandas as pd
T1 = pd.merge(T1, T2, on=T1.index, how='outer')

Example 5: python - join two columns and transform it as index

df = DataFrame({'var_1':['a','b','c'], 'var_2':[1, 2, 3], 'var_3':['apple', 'banana', 'pear']})
cols = ['var_1', 'var_2']    # Set columns to combine
df['combined'] = df[cols].apply(lambda row: ', '.join(row.values.astype(str)), axis=1)

# Define which column is index
df_i = df.set_index('combined') 

# Set the index to None
df_i.index.names = [None]

Example 6: how to merge two column pandas

DataFrame["new_column"] = DataFrame["column1"] + DataFrame["column2"]