Precision Handling in Python | floor, ceil, round, trunc, format
Learn the different methods for precision handling of floating-point numbers.
Precision handling is a process of rounding off the values of floating-point numbers. Python has many built-in functions to handle the precision, like floor, ceil, round, trunc, and format. Let's discuss the different types of precision handling in Python.
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Some of these methods require the math module to be imported.
floor() function in Python¶
The floor function returns the largest integer less than or equal to a given number. Let's take an example to understand the floor function:
import math
value = 34.185609
print(math.floor(value))
# 34
value = -34.185609
print(math.floor(value))
# -35
ceil() function in Python¶
The ceil function returns the smallest integer greater than or equal to a given number. Let's take an example to understand the ceil function:
import math
value = 34.185609
print(math.ceil(value)
# 35
value = -34.185609
print(math.ceil(value)
# -34
trunc() function in Python¶
The trunc function returns the integer part of a number by removing all the decimal parts from a floating-point number. Let's take an example to understand the trunc function:
import math
value = 34.185609
print(math.trunc(value))
# 34
value = -34.185609
print(math.trunc(value))
# -34
round() function in Python¶
The round function rounds off the output in a customized format. We can pass the number of decimal places as an argument, and it then rounds a number to the given precision in decimal digits. Let's take an example to understand the round function:
value = 34.185609
print(round(value, 2))
# 34.19
print(round(value, 3))
# 34.186
print(round(value, 4))
# 34.1856
Interesting fact: round() can also take a negative integer as second argument:
value = 1346.185609
print(round(value, 0))
# 1346.0
print(round(value, -1))
# 1350.0
print(round(value, -2))
# 1300.0
print(round(value, -3))
# 1000.0
Formatting with f-Strings in Python¶
f-Strings can be used to format values in a String:
value = 34.185609
print(f'The value is: {value:.2f}')
# The value is: 34.19
print(f'The value is: {value:.3f}')
# The value is: 34.186
format() function in Python¶
The format function can also be used to format the output. Let's take an example to understand the format function:
value = 34.185609
print('The value is {0:.2f}'.format(value))
# The value is 34.19
% formatting operator in Python¶
And similar, the % operator can be used to format and set the precision of the output:
value = 34.185609
print('The value is: %.3f' % value)
# The value is: 34.186
Conclusion¶
In this article, we have discussed the different types of precision handling in Python. We have also discussed the different types of formatting in Python.
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