python - Create a column based on condition pertaining to 2 other columns -

i have 2 columns in pandas dataframe (let's call 'col1' , col2'). both contain true/false values.

i need create third column these 2 ('col3'), have true value record if 1 or other of 2 columns has true value in record.

currently, i'm doing with:

col3 = []  index, row in df.iterrows():     if df.ix[index, 'col1'] == true or df.ix[index, 'col2'] == true:         col3.append(true)     else:         col3.append(false)  df['col3'] = col3 

it works fast enough size of dataset, there way in one-liner/vectorized way? perhaps using 2 nested np.where() statements?

you can use np.logical_or this:

in [236]: df = pd.dataframe({'col1':[true,false,false], 'col2':[false,true,false]}) df  out[236]:     col1   col2 0   true  false 1  false   true 2  false  false  in [239]: df['col3'] = np.logical_or(df['col1'], df['col2']) df  out[239]:     col1   col2   col3 0   true  false   true 1  false   true   true 2  false  false  false 

or use | operator:

in [240]: df['col3'] = df['col1'] | df['col2']  df out[240]:     col1   col2   col3 0   true  false   true 1  false   true   true 2  false  false  false