20 lines
287 B
Python
20 lines
287 B
Python
#!/usr/bin/env python
|
|
# -*- encoding: utf-8 -*-
|
|
"""
|
|
Topic: 函数默认参数
|
|
Desc :
|
|
"""
|
|
|
|
def spam(a, b=42):
|
|
print(a, b)
|
|
|
|
spam(1) # Ok. a=1, b=42
|
|
spam(1, 2) # Ok. a=1, b=2
|
|
|
|
_no_value = object()
|
|
|
|
def spam(a, b=_no_value):
|
|
if b is _no_value:
|
|
print('No b value supplied')
|
|
|