Rounding numbers using the for loop

Question

I'm trying to figure out how to show only one digit after the decimal point in a Celsius to Fahrenheit conversion assignment. The only one coming up with multiple digits thus far is 13 degrees Celsius, which ends up as 55.400000000000006. My for statement looks like this.

def main():
    for ct in range (0, 21):
        fe = 9 / 5 * (ct) + 32
        print (ct, "Celsius equals", fe, "Fahrenheit")

Like I said, the program runs as expected, I just would like to clean that one conversion up.

Please tag with relevant tags. You want help with `rounding` in `python`, and your question has nothing to do with `using` or `loops` (or `for-loop`). — Amadan, May 08 '15 at 01:06
possible duplicate of [Limiting floats to two decimal points](http://stackoverflow.com/questions/455612/limiting-floats-to-two-decimal-points) — Scott Hunter, May 08 '15 at 01:09

score 1 · Answer 1 · answered May 08 '15 at 01:12

1

print("%d Celsius equals %.1f Fahrenheit" % (ct, fe))
# => 13 Celsius equals 55.4 Fahrenheit

answered May 08 '15 at 01:12

Amadan

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score 0 · Answer 2 · answered May 08 '15 at 01:09

0

You can use the python function round().

https://docs.python.org/2/library/functions.html#round

I believe the proper usage would be round(fe, 1).

answered May 08 '15 at 01:09

Jeremy

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score 0 · Answer 3 · answered May 08 '15 at 01:10

It looks like you might be using Python. To format your code, put four blank spaces before each line so that it is more readable, like this:

def main(): 
    for ct in range (0, 21): 
        fe = 9 / 5 * (ct) + 32 
        print (ct, "Celsius equals", fe, "Fahrenheit")

If you want to round your answer, use Python's round() function. This would make your print statement something like this: print (ct, "Celsius equals", round(fe, 1), "Fahrenheit")

score 0 · Answer 4 · answered May 08 '15 at 01:13

0

import math
def main():
    for ct in range (0, 21):
        fe = 9 / 5 * (ct) + 32
        print(ct, "Celsius equals", (math.ceil(fe*100)/100) , "Fahrenheit")

This might work.

answered May 08 '15 at 01:13

Gavin Hardison

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score 0 · Answer 5 · edited May 23 '17 at 12:21

0

You can show one decimal point without having to use another operator like round or math.ceil. (In python 2.7 this would be)

'%.1f' % (5.34)

Here are some quirks of using the round function that you should be aware of : round() in Python doesn't seem to be rounding properly

edited May 23 '17 at 12:21

Community

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answered May 08 '15 at 02:38

fixxxer

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Rounding numbers using the for loop

5 Answers5