Python 3.14+Numbers & mathfunction

complex.from_number()

complex numbers

Class method that builds a complex number from a single numeric argument (delegates to __complex__, then __float__, then __index__). Unlike complex(), it does not accept strings. Python 3.14+.

Syntax

classmethod complex.from_number(x)

The method landed in 3.14, so on older interpreters — graders included — touching it raises AttributeError; plain complex(x) stays the portable choice. Its whole point is strictness: exactly one numeric argument, and a string gets a TypeError, whereas complex('1+2j') happily parses text — handy for user input, dangerous when you expected a number.

Examples

print(complex.from_number(3))  # → (3+0j)
print(complex.from_number(2.5))  # → (2.5+0j)
print(complex.from_number(1+2j))  # → (1+2j)
print(complex.from_number(True))  # → (1+0j)
try: complex.from_number('1+2j')  # строка не число
except TypeError as e: print(type(e).__name__)  # → TypeError

See also

Common errors

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