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Ben Robinson
7,380 PointsHow do you add numbers in a string?
I'm trying to learn Python and I do have other language experience, but I'm having problems getting my list of numbers to add together to make a sum. Here's my code at this point:
num_list = []
def add_list(num):
for num in num_list:
total_num = num
return((total_num + num))
continue
while True:
num = input("")
if num == 'done':
break
num_list.append(num)
print(add_list(num))
continue
This is for a challenge in the Python Basics course and I've been working on this for the past few days. I'm just so lost. Any advice?
Kenneth Love
Treehouse Guest TeacherI edited your post for proper code highlighting.
3 Answers
Ratik Sharma
32,885 PointsThe question in code challenge is as follows if I'm not wrong: Make a function named add_list that adds all of the items in a passed-in list together and returns the total. Assume the list contains only numbers. You'll probably want to use a for loop. The solution to this is as follows:
# Here we're defining the function the takes a list (the list only needs to have numbers as per the question so no need to convert strings)
def add_list(numbers):
# We initialise a variable 'total' to 0. This is our summing variable.
total = 0
# We start our for loop going through each number in the list and adding it to variable total
for number in numbers:
total += number
# After adding up, we return total
return total
# This is the second function we need to define which calls the add_list function to summarise
def summarize(list):
# Using a return statement is enough here (as per the challenge). Note that we use call add_list from within format()
return "The sum of {} is {}.".format(list, add_list(list))
Note: Be careful about the indentation while typing out Python code. If this helps, mark it as a top answer so others can refer to it!
Jason Anello
Courses Plus Student 94,610 PointsHi Ratik,
You should use a different variable name and not list
In your for loop, number is a number from the list so you should just add it to your total
total += number
You're using it to access the list at a particular index and this will probably lead to accessing the list out of bounds.
Ben Robinson
7,380 PointsThank you very much! This makes so much sense now. :D
Edward Pham
9,179 PointsYou can convert strings into integers by using int(). So in your case, when you append num to the list, you'd just do num_list.append(int(num)).
Thomas Ton
9,836 PointsThis is how I did it. Hope it helps!
def add_list(some_list):
return sum(some_list)
def summarize(another_list):
return "The sum of {} is {}".format(another_list, add_list(another_list))
Jason Anello
Courses Plus Student 94,610 PointsJason Anello
Courses Plus Student 94,610 PointsHi Ben,
See Ratik's answer and what I think should be corrected.
It seems as if you're trying to do too much here and write a complete program rather than just the function definition.
Don't worry about the list itself or calling your function. The challenge will call your function for you and pass in a list when testing.