bool() Boolean conversion
Last updated: 2026-09-22
bool() Boolean conversion
bool() converts a value to boolean; returns False for 0, 0.0, empty strings/containers and None, True otherwise.
| Category | Built-in Functions |
|---|---|
| Kind | Built-in Function |
| Python Version | all |
📝 Syntax
bool(x)⚙️ Parameters
| x Optional | Any object to test truthiness; omitted yields False.（Default：None） |
|---|
Returns：bool. The truth value of x (True or False).
▶ Example
Edit the code, press Run, and see the result in the output panel:
Output：
False
False
True
False💡 Tip Customize truthiness via __bool__.
🏷️ Related Built-in Functions
💡 Related Cases
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❓ FAQ
QWhich values does bool() evaluate to False?
AOnly these falsy values: 0, 0.0, 0j, '', [], (), {}, set(), None, False; everything else (including non-empty strings and non-empty containers) is True.
QIs bool('0') True or False?
AIt is True. '0' is a non-empty string and non-empty means truthy; only the empty string '' is False. Likewise bool('False') is also True.
QIs there a difference between bool() and testing directly in an if statement?
ANo difference. if x: internally calls bool(x), so they are equivalent; bool() just makes the truthiness result explicit.
QWhat does bool() return when called without arguments?
AIt returns False; the x argument is optional.
