十一、python函數學習
1. 定義函數
def 函數名(形參):
函數體
return xxx--------其下面的內容不再執行
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2.執行函數
函數名(實參)
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3.形參，實參（默認按照順序）
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4.執行形參傳入實參，可不按照順序
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5.函數可以有默認參數
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6.動態參數
#動態參數一,類型為元祖，傳的參數為元祖的元素
def f1(*a):
print (a,type(a))
f1(123,234,[456123789],{1:2})
#動態參數二，類型為字典，傳入的參數為字典的鍵值對
def f1(**a):
print (a,type(a))
f1(k1=123,k2=456)
#萬能動態參數-------一*較**在前
def f1(*a,**p):
print (a,type(a),type(p))
f1(123,234,[456123789],{1:2},k1=123,k2=456)
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((123, 234, [456123789], {1: 2}), <type ‘tuple‘>)
({‘k2‘: 456, ‘k1‘: 123}, <type ‘dict‘>)
((123, 234, [456123789], {1: 2}), <type ‘tuple‘>, <type ‘dict‘>)
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7.為動態參數傳入字典，列表
def f1(*args):
print (args,type(args))
l1=[11,22,33,44]
f1(l1)
f1(*l1)
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(([11, 22, 33, 44],), <type ‘tuple‘>)
((11, 22, 33, 44), <type ‘tuple‘>)
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def f2(**args):
print (args,type(args))
l1={"k1":"123"}
f2(l1=l1)
f2(**l1)
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({‘l1‘: {‘k1‘: ‘123‘}}, <type ‘dict‘>)
({‘k1‘: ‘123‘}, <type ‘dict‘>)
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8.全局變量，局部變量
P="chushujin"
def func1():
#局部變量
a=123
global P #加上此關鍵詞後，全局變量就會被修改，否則不會被修改
print (a)
P="zhangyu"
def func2():
print (P)
func1()
func2()
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123
zhangyu
十一、python函數學習