How to round to 2 decimals with Python?

user_3080434 0
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I am getting a lot of decimals in the output of this code (Fahrenheit to Celsius converter).

My code currently looks like this:

def main():
    printC(formeln(typeHere()))

def typeHere():
    global Fahrenheit
    try:
        Fahrenheit = int(raw_input("Hi! Enter Fahrenheit value, and get it in Celsius!\n"))
    except ValueError:
        print "\nYour insertion was not a digit!"
        print "We've put your Fahrenheit value to 50!"
        Fahrenheit = 50
    return Fahrenheit

def formeln(c):
    Celsius = (Fahrenheit - 32.00) * 5.00/9.00
    return Celsius

def printC(answer):
    answer = str(answer)
    print "\nYour Celsius value is " + answer + " C.\n"



main()

So my question is, how do I make the program round every answer to the 2nd decimal place?

rounding python
21 Answers

If you just want to print the rounded result out, you can use the f-strings introduced since Python 3.6. The syntax is the same as str.format()'s format string syntax, except you put a f in front of the literal string, and you put the variables directly in the string, within the curly braces.

.2f indicates rounding to two decimal places:

number = 3.1415926
print(f"The number rounded to two decimal places is {number:.2f}")

Output:

The number rounded to two decimal places is 3.14
user_81707140

If you need avoid floating point problem on rounding numbers for accounting, you can use numpy round.

You need install numpy : 

pip install numpy

and the code : 

import numpy as np

print(round(2.675, 2))
print(float(np.round(2.675, 2)))

prints

2.67
2.68

You should use that if you manage money with legal rounding.

user_31281220

You can use round operator for up to 2 decimal 

num = round(343.5544, 2)
print(num) // output is 343.55
user_84635550

If you need not only round result but elso do math operations with round result, then you can use decimal.Decimal https://docs.python.org/2/library/decimal.html

from decimal import Decimal, ROUND_DOWN

Decimal('7.325').quantize(Decimal('.01'), rounding=ROUND_DOWN)
Decimal('7.32')
user_65157550 
from decimal import Decimal, ROUND_HALF_UP

# Here are all your options for rounding:
# This one offers the most out of the box control
# ROUND_05UP       ROUND_DOWN       ROUND_HALF_DOWN  ROUND_HALF_UP
# ROUND_CEILING    ROUND_FLOOR      ROUND_HALF_EVEN  ROUND_UP

our_value = Decimal(16.0/7)
output = Decimal(our_value.quantize(Decimal('.01'), 
rounding=ROUND_HALF_UP))
print output
user_27910670

To avoid surprising value from round() this is my approche:

Round = lambda x, n: eval('"%.'+str(int(n))+'f" % '+repr(int(x)+round(float('.'+str(float(x)).split('.')[1]),n)))

print(Round(2, 2))       # 2.00
print(Round(2.675, 2))   # 2.68
user_89947220

Here is an example that I used:

def volume(self):
    return round(pi * self.radius ** 2 * self.height, 2)

def surface_area(self):
    return round((2 * pi * self.radius * self.height) + (2 * pi * self.radius ** 2), 2)
user_57042510
user_80250860

The easiest solution I found so far, dunno why people ain't using it.

# Make sure the number is a float
a = 2324.55555
# Round it according to your needs
# dPoints is the decimals after the point
dPoints = 2
# this will round the float to 2 digits
a = a.__round__(dPoints)
if len(str(a).split(".")[1]) < dPoints:
    # But it will only keep one 0 if there is nothing,
    # So we add the extra 0s we need
    print(str(a)+("0"*(dPoints-1)))
else:
    print(a)
user_142087770

Truncating to 2 digitis:

somefloat = 2.23134133
truncated = int( somefloat * 100 ) / 100  # 2.23
user_49346400

Simple example

bill = 10.24 print(round(10.241))

user_52064590
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