Looping and nested loops

[buran]

It looks you are using python2. If you were using python3, you will get ValueError, not NameError (line #9). See https://python-forum.io/Thread-Python3-2...-raw-input for more details. If this is the case you are strongly advised to switch to python3, because python2 support ends 1 January 2020.

what you have is close to what you want. You need to store the daily rain data in a list so that you can calculate average later.

all_days = ("Monday", "Tuesday", "Wednesday", "Thursday","Friday", "Saturday", "Sunday")
 
# number of weeks
while True:
    try:
        total_weeks = int(input("Enter number of weeks for which rainfall should be calculated "))
    except ValueError:
        print("Number of weeks must be an interger")
    else:
        if total_weeks < 1:
            print("Number of weeks must be at least 1")
        else:
            break

daily_rain = []
for week in range(1, total_weeks+1):
    for day in all_days:
        rain = int(input("enter the rain for {} in week {}:".format(day, week))) # in 3.6+ this could be rain = int(input(f"enter the rain for {day} in week {week}:"))
        daily_rain.append(rain)
        
# change the code above so that you can handle wron input for rain, i.e. you want number - int/float      
# add code to calculate average