Python 3.14+Numbers & mathfunction

float.from_number()

type conversion

Class method building a float from a number (int, float or an object with __float__). Unlike float(), it rejects strings. Python 3.14+.

Syntax

float.from_number(x)

The method exists to separate "convert a number" from "parse a string": float() does both, so a string that sneaks in from input() is silently accepted. from_number raises TypeError on str and bytes, yet it does not shield you from precision loss — a Decimal with a long mantissa is rounded, and an int too large for a float raises OverflowError.

Examples

print(float.from_number(7))                 # → 7.0
print(float.from_number(-2.5))              # → -2.5

from decimal import Decimal
print(float.from_number(Decimal('1.25')))   # → 1.25

from fractions import Fraction
print(float.from_number(Fraction(1, 4)))    # → 0.25

See also

Common errors

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