在写程序时，经常会碰见传递过多参数的情况。先看一个例子
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| #!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: wxnacy([email protected])
def func1(id, name, age, **kw):
amount = 1
duration = 10
func2(id = id, name = name, age = age, amount = amount, **kw)
def func2(**kw):
print(kw)
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在 func1() 给 func2() 传递参数，一个一个的写真的很痛苦，写一次还好，关键是到处都有这种情况。
可不可以将想要的参数打包直接传递过去呢？
内置方法 locals() 就可以达到这个效果，它可以实时收集当前作用域的参数，并返回一个字典。
先在全局范围内看看有哪些参数
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| #!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: wxnacy([email protected])
if __name__ == "__main__":
print(locals())
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| $ python locals_demo.py
{'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external.SourceFileLoader object at 0x102c75860>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, '__file__': 'locals_demo.py', '__cached__': None}
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可能你到没注意到一个空文件里都有这么多的内置参数。
locals() 收集参数是实时进行的，比如我们定义一个参数
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| #!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: wxnacy([email protected])
if __name__ == "__main__":
print(locals())
name = 'wxnacy'
print(locals())
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| $ python locals_demo.py
{'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external.SourceFileLoader object at 0x1083d5860>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, '__file__': 'locals_demo.py', '__cached__': None}
{'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external.SourceFileLoader object at 0x1083d5860>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, '__file__': 'locals_demo.py', '__cached__': None, 'name': 'wxnacy'}
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第二次打印的结果中，就多出了刚刚定义的参数 name
在方法中使用也是如此
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| #!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: wxnacy([email protected])
def func(**kw):
name = 'wxnacy'
print(locals())
if __name__ == "__main__":
func(url = 'https://wxnacy.com')
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| $ python locals_demo.py
{'kw': {'url': 'https://wxnacy.com'}, 'name': 'wxnacy'}
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因为 locals() 方法的值是动态变的，所以我们可以先用变量储存起来，并且记得去掉不需要的参数
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| #!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: wxnacy([email protected])
def func(id, age, **kw):
name = 'wxnacy'
args = locals()
args.pop('name')
print(args)
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或者
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| #!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: wxnacy([email protected])
def func(id, age, **kw):
args = locals()
name = 'wxnacy'
print(args)
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现在再来回顾下开始的问题，这下解决方式简单了很多
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| #!/usr/bin/env python
# -*- coding:utf-8 -*-
# Author: wxnacy([email protected])
def func1(id, name, age, **kw):
amount = 1
args = locals()
duration = 10
func2(**args)
def func2(**kw):
print(kw)
|
喔噢，我爱 Python。