Creating a new column based on if condition but getting error in python

i want new column ['pred_n'] to be created based on certain condition, condition is as follows: if year is less than or equal to current year & month is less than current month, pred_n should be equal to yhatpct else it should be yhatpct_ft. trying following syntax:

if((dfyz['year_x'] <     datetime.now().year) | ((dfyz['year_x'] == datetime.now().year) & (dfyz['mon'] < datetime.now().month))):
    dfyz['pred_n'] = dfyz['yhat']*dfyz['pct']
else:
    dfyz['pred_n'] = dfyz['yhat']*dfyz['pct_ft']

but i am not getting anything for else condition