python函数中的return

Ⅰ python怎么return后让循环继续运行

return 会直接另函数返回，函数就运行结束了，所有该函数体内的代码都不再执行了，所以该函数体内的循环也不可能再继续运行。

如果你需要让循环继续执行，就不能return函数，而应该选用break或者continue。
break：跳出所在的当前整个循环，到外层代码继续执行。
continue：跳出本次循环，从下一个迭代继续运行循环，内层循环执行完毕，外层代码继续运行。
return：直接返回函数，所有该函数体内的代码（包括循环体）都不会再执行。

用下边的示例代码来解释：

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def return_continue_break(type):
if(not type in ["return", "continue", "break"]):
print '"type" should be "return, continue, break".'
return
for j in range(0, 10):
for i in range(0, 10):
print "j_i: %d_%d" %(j, i)
if(i > 3):
if(type == "return"):
return
elif(type == "continue"):
continue
else:
break
print "executed!"

if __name__ == '__main__':
return_continue_break("break")
return_continue_break("continue")
return_continue_break("return")

BREAK的输出为：

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j_i: 0_0
executed!
j_i: 0_1
executed!
j_i: 0_2
executed!
j_i: 0_3
executed!
j_i: 0_4
j_i: 1_0
executed!
j_i: 1_1
executed!
j_i: 1_2
executed!
j_i: 1_3
executed!
j_i: 1_4
j_i: 2_0
executed!
j_i: 2_1
executed!
j_i: 2_2
executed!
j_i: 2_3
executed!
j_i: 2_4
j_i: 3_0
executed!
j_i: 3_1
executed!
j_i: 3_2
executed!
j_i: 3_3
executed!
j_i: 3_4
j_i: 4_0
executed!
j_i: 4_1
executed!
j_i: 4_2
executed!
j_i: 4_3
executed!
j_i: 4_4
j_i: 5_0
executed!
j_i: 5_1
executed!
j_i: 5_2
executed!
j_i: 5_3
executed!
j_i: 5_4
j_i: 6_0
executed!
j_i: 6_1
executed!
j_i: 6_2
executed!
j_i: 6_3
executed!
j_i: 6_4
j_i: 7_0
executed!
j_i: 7_1
executed!
j_i: 7_2
executed!
j_i: 7_3
executed!
j_i: 7_4
j_i: 8_0
executed!
j_i: 8_1
executed!
j_i: 8_2
executed!
j_i: 8_3
executed!
j_i: 8_4
j_i: 9_0
executed!
j_i: 9_1
executed!
j_i: 9_2
executed!
j_i: 9_3
executed!
j_i: 9_4

RETURN的输出为：

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j_i: 0_0
executed!
j_i: 0_1
executed!
j_i: 0_2
executed!
j_i: 0_3
executed!
j_i: 0_4

CONTINUE的输出为：

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j_i: 0_0
executed!
j_i: 0_1
executed!
j_i: 0_2
executed!
j_i: 0_3
executed!
j_i: 0_4
j_i: 0_5
j_i: 0_6
j_i: 0_7
j_i: 0_8
j_i: 0_9
j_i: 1_0
executed!
j_i: 1_1
executed!
j_i: 1_2
executed!
j_i: 1_3
executed!
j_i: 1_4
j_i: 1_5
j_i: 1_6
j_i: 1_7
j_i: 1_8
j_i: 1_9
j_i: 2_0
executed!
j_i: 2_1
executed!
j_i: 2_2
executed!
j_i: 2_3
executed!
j_i: 2_4
j_i: 2_5
j_i: 2_6
j_i: 2_7
j_i: 2_8
j_i: 2_9
j_i: 3_0
executed!
j_i: 3_1
executed!
j_i: 3_2
executed!
j_i: 3_3
executed!
j_i: 3_4
j_i: 3_5
j_i: 3_6
j_i: 3_7
j_i: 3_8
j_i: 3_9
j_i: 4_0
executed!
j_i: 4_1
executed!
j_i: 4_2
executed!
j_i: 4_3
executed!
j_i: 4_4
j_i: 4_5
j_i: 4_6
j_i: 4_7
j_i: 4_8
j_i: 4_9
j_i: 5_0
executed!
j_i: 5_1
executed!
j_i: 5_2
executed!
j_i: 5_3
executed!
j_i: 5_4
j_i: 5_5
j_i: 5_6
j_i: 5_7
j_i: 5_8
j_i: 5_9
j_i: 6_0
executed!
j_i: 6_1
executed!
j_i: 6_2
executed!
j_i: 6_3
executed!
j_i: 6_4
j_i: 6_5
j_i: 6_6
j_i: 6_7
j_i: 6_8
j_i: 6_9
j_i: 7_0
executed!
j_i: 7_1
executed!
j_i: 7_2
executed!
j_i: 7_3
executed!
j_i: 7_4
j_i: 7_5
j_i: 7_6
j_i: 7_7
j_i: 7_8
j_i: 7_9
j_i: 8_0
executed!
j_i: 8_1
executed!
j_i: 8_2
executed!
j_i: 8_3
executed!
j_i: 8_4
j_i: 8_5
j_i: 8_6
j_i: 8_7
j_i: 8_8
j_i: 8_9
j_i: 9_0
executed!
j_i: 9_1
executed!
j_i: 9_2
executed!
j_i: 9_3
executed!
j_i: 9_4
j_i: 9_5
j_i: 9_6
j_i: 9_7
j_i: 9_8
j_i: 9_9

Ⅱ python中return函数的用法

在 Python 中，“return”函数的用法如下：

1、return 语句用于退出函数，终止函数并将 return 值传回。实例：

>>>defa(x,y):
>>>ifx==y:
>>>returnx,y

2、用于同一循环语句下，遇到第一个 return 后即返回。实例：

```python
>>>deffun(a,b):
print(a)
returna
print(b)
returnb

>>>resunlt=fun(2,6)
2
```

3、用于 return 在不带参数的情况下（或者没有写 return 语句），默认返回 None。实例：

defrecurve(a,b):
ifa%b==0:
returnb
else:
gcd(b,a%b)

以上内容参考：网络-Python