Nested while and for loops in Python

Question

I want to write a program that asks the user for number of years and then the temperature for each month for as many number of years as they have decided in the input like this:

Which is the first year?: 2015

Month 1: 25 

Month 2: 35 
.
.
.

for 12 months and I have written a code that works for that:

This is the outer loop for years:

loops = int(input("How many years?: "))
count = 1

while count < loops:
  for i in range (0,loops):
    input("Which is the " + str(count) + ": year?: ")
    count += 1

This is the inner loop for months:

monthnumber = 1

for i in range(0,12):
        input("Month " + str(monthnumber) + ": ")
        monthnumber += 1

My question is, where do I place the inner loop for months so that the code continues like this:

Which is the 1 year? (input e.g. 2015)

Month 1: (e.g. 25)

Month 2: (e.g. 35)
..... for all twelve months and then continue like this

Which is the 2 year? (e.g. 2016)

Month 1:

Month 2:

I have tried putting it in different places but without success.

The6thSense · Accepted Answer · 2015-10-09 12:24:48Z

2

There is no need for while loop two for loop is enough

Code:

loops = int(input("How many years?: "))
for i in range (1,loops+1):
    save_to_variable=input("Which is the " + str(i) + ": year?: ")
    for j in range(1,13):
         save_to_another_variable=input("Month " + str(j) + ": ")

Edited Code:

loops = int(input("How many years?: "))
count = 1
while count < loops:            
    save_to_variable=input("Which is the " + str(count) + ": year?: ")
    for j in range(1,13):
         save_to_another_variable=input("Month " + str(j) + ": ")
    count+=1

edited Oct 9, 2015 at 12:24

answered Oct 6, 2015 at 11:11

The6thSense

8,3459 gold badges37 silver badges67 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

J.Se Over a year ago

Thanks, but the task is using a while loop with a for loop inside it, nested. Any idea of how I can use the code I have, but only place the inner for loop so that it is correct?

The6thSense Over a year ago

@J.Se IF you really need to do it using while then place just add the while loop above first for loop

J.Se Over a year ago

@vigneskalai could you please show me how you mean?

Christian Witts · Accepted Answer · 2015-10-06 11:11:36Z

1

You can embed your inner month loop inside each iteration of the year loop, like below. This will ask for the year number once, followed by 12 questions for each months reading, followed by the next iteration.

from collections import defaultdict
loops = int(input("How many years?: "))
temperature_data = defaultdict(list)
for i in range(loops):
    year = input("Which is the " + str(i) + ": year?: ")
    for m in range(12):
        temperature_reading = input("Month " + str(m) + ": ")
        temperature_data[year].append(temperature_reading)

answered Oct 6, 2015 at 11:11

Christian Witts

11.7k1 gold badge36 silver badges47 bronze badges

1 Comment

J.Se Over a year ago

Thanks for replying, but isn't there any way just to keep everything the way I have done it and put the inner loop somewhere to achieve the same result? It has to be a while loop with a for loop inside it.

Collectives™ on Stack Overflow

Nested while and for loops in Python

2 Answers 2

3 Comments

1 Comment

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

1 Comment

Related