I want to create a new column that will hold the week number in the month ie (week 1, week 2 etc...)

I created a date range for each weeks and used if condition to fill the new columns but it doesnt work I keep getting errors

week1 = df[(df['start_time'] >= '2019-02-01') & (df['start_time'] <= '2019-02-07')]
week2 = df[(df['start_time'] >= '2019-02-08') & (df['start_time'] <= '2019-02-14')]
week3 = df[(df['start_time'] >= '2019-02-15') & (df['start_time'] <= '2019-02-21')]
week4 = df[(df['start_time'] >= '2019-02-22') & (df['start_time'] <= '2019-02-28')]

if df['start_time'] == week1:
    df['trip_week'] = 'Week 1'
    
elif df['start_time'] == week2:
    df['trip_week'] = 'Week 2'
    
elif df['start_time'] == week3:
    df['trip_week'] = 'Week 3'
    
else:
    df['trip_week'] = 'Week 4'

Expected Output

CodePudding user response：

This will work:

df["trip_week"] = "Week "   ((df["start_time"].dt.day // 7)   1).astype(str)

Adds a column with "Week " followed by the integer of the week (dividing the day of the month by 7 - floor division - and adding 1).