CODEWITHSUNDEEP
pythonfunctionrangepython-3.4
Connor Mooneyhan
Connor Mooneyhan

Reputation: 557

Python 3 defining a function to print a range of floats

I was trying to define a simple function to find the range between two floats, and this is what I got:

def item(number, terminator, step):
    while number < terminator:
        return (number)
        number += step

item(1.00, 1.12, 0.01)

The console doesn't print any errors, it doesn't print None, it just doesn't do anything. It runs the program and does nothing. I am very confused. What is wrong with my code?

Upvotes: 0

Views: 74

Answers (1)

Martijn Pieters
Martijn Pieters

Reputation: 1121554

There are two things wrong:

  1. You are not printing anything. The item() function returns and you ignored the return value. The Python interactive interpreter echoes almost everything you do but a regular script requires you to explicitly print.

  2. You are returning the first value of the range. return ends a function.

You could build a list of values first, and return that, then print the result:

def item(number, terminator, step):
    items = []
    while number < terminator:
        items.append(number)
        number += step
    return items

print(item(1.00, 1.12, 0.01))

Demo:

>>> def item(number, terminator, step):
...     items = []
...     while number < terminator:
...         items.append(number)
...         number += step
...     return items
... 
>>> print(item(1.00, 1.12, 0.01))
[1.0, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.1, 1.11]

Alternatively, use yield instead of return to turn your function into a generator, and loop over the results:

def item(number, terminator, step):
    while number < terminator:
        yield number
        number += step

for value in item(1.00, 1.12, 0.01):
    print(value)

which produces:

>>> def item(number, terminator, step):
...     while number < terminator:
...         yield number
...         number += step
... 
>>> for value in item(1.00, 1.12, 0.01):
...     print(value)
... 
1.0
1.01
1.02
1.03
1.04
1.05
1.06
1.07
1.08
1.09
1.1
1.11

Upvotes: 2

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