Answers for "add two string columns in pandas"

python merge strings in columns

df["period"] = df["Year"].astype(str) + df["quarter"]

pandas dataframe add two columns int and string

df1 = df['1st Column Name'].map(str) + df['2nd Column Name'].map(str) + ...

pandas dataframe add two columns int and string

df = df['Day'].map(str) + '-' + df['Month'].map(str) + '-' + df['Year'].map(str)