How to use a return statement in a for loop?
Using a return
inside of a loop will break it and exit the function even if the iteration is still not finished.
For example:
def num():
# Here there will be only one iteration
# For number == 1 => 1 % 2 = 1
# So, break the loop and return the number
for number in range(1, 10):
if number % 2:
return number
>>> num()
1
In some cases we need to break the loop if some conditions are met. However, in your current code, breaking the loop before finishing it is unintentional.
Instead of that, you can use a different approach:
Yielding your data
def show_todo():
# Create a generator
for key, value in cal.items():
yield value[0], key
You can call it like:
a = list(show_todo()) # or tuple(show_todo())
or you can iterate through it:
for v, k in show_todo(): ...
Putting your data into a list or other container
Append your data to a list, then return it after the end of your loop:
def show_todo():
my_list = []
for key, value in cal.items():
my_list.append((value[0], key))
return my_list
Or use a list comprehension:
def show_todo():
return [(value[0], key) for key, value in cal.items()]
Use a generator syntax (excellent explanation on SO here):
def show_todo():
for key, value in cal.items():
yield value[0], key
for value, key in show_todo():
print(value, key)