Float
A number with a decimal point, e.g. 3.14.
A float is a number with a decimal point, used for measurements and any value that isn't whole. The division operator / always produces a float, even for something like 10 / 2. Floats are stored in binary, so a few decimals can't be represented exactly and you may see a tiny rounding error.
price = 3.14
print(price * 2) # 6.28
print(10 / 2) # / always gives a float -> 5.0
print(0.1 + 0.2) # a tiny rounding error appears
print(round(0.1 + 0.2, 2)) # round for display
Output
6.28 5.0 0.30000000000000004 0.3
Where this shows up in real Python
Floats handle anything with a fractional part: averages, prices, measurements, and percentages.
Commonly used Float tools
float('3.14')— parse a decimal stringround(x, 2)— round to a number of decimal placesabs(x)— drop the signf'{x:.2f}'— format to a fixed number of decimalsimport math— math.floor, math.ceil, math.sqrt, …
Official documentation: Python Tutorial: Floating-Point Arithmetic — Issues and Limitations