switch = {(0,21): 'never have a pension',
(21,50): 'might have a pension',
(50,65): 'definitely have a pension',
(65, 200): 'already collecting pension'}
for key, value in switch:
a=input()
if key[0] < a< key[1]:
print(value)
when I try to execute the program it raise an error
TypeError: 'int' object is not subscriptable.
I don't know how to fix. please help
When you do for kev, value in switch, you're not getting the tuple and the string - you're getting the two values from the tuple. This is because iterating over a dictionary by default iterates over its keys.
Instead, you want to do for key, value in switch.items().
I suppose you would like to do:
while True:
try:
a = int(input())
except ValueError:
print('not an int, try again')
for k, v in switch.items():
if k[0] < a < k[1]:
print(v)
And depending your needs:
>>> [v for k, v in switch.items() if k[0] < a < k[1]]
['might have a pension']
By the way, this is a fairly unpythonic way to do a multi-range test.
Consider this if-elif tree instead:
a = input()
if a < 21:
msg = 'never have a pension'
elif a < 50:
msg = 'might have a pension'
elif a < 65:
msg = 'definitely have a pension'
else:
msg = 'already collecting pension'
print msg
Advantages: it is simpler to understand, avoids duplicating the endpoints (which are most likely to change), works even if people somehow manage to live past 200, and actually avoids a bug in your original code (where people would already be collecting a pension if they were exactly 21).
Disadvantages: code is longer, and msg and a are repeated. However, this is offset by the fact that you can now implement more customizable and appropriate logic under each case.
