python基础入门----break和continue语句

原文链接:https://www.programiz.com/python-programming/break-continue

Python break and continue

In this article, you will learn to use break and continue statements to alter the flow of a loop.

Table of Contents

python break和continue语句

在这篇文章中,你将学习使用break和continue语句去改变一个循环流程。

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What is the use of break and continue in Python?

In Python, break and continue statements can alter the flow of a normal loop.

Loops iterate over a block of code until test expression is false, but sometimes we wish to terminate the current iteration or even the whole loop without checking test expression.

The break and continue statements are used in these cases.

什么时候使用break和continue?

 在python中,break和continue语句可以改变一个正常的循环。

循环遍历整个代码块直到测试表达式是错误,但是有时我们希望终止当前循环或甚至整个循环,在没有检查测试表达式时。

这个break和continue语句被使用在这种情况下。


Python break statement

The break statement terminates the loop containing it. Control of the program flows to the statement immediately after the body of the loop.

If break statement is inside a nested loop (loop inside another loop), break will terminate the innermost loop.

break语句

这个循环包含break终止循环,包含它他。语句立即控制后面主体循环程序流程。

如果break语句是在一个内嵌循环里面(循环包含另外一个循环),break将终止最里面循环。


Syntax of break

break语法

break

Flowchart of break

break流程图

python基础入门----break和continue语句

The working of break statement in for loop and while loop is shown below.

在for循环break语句的工作,while循环的工作显示在下面。

python基础入门----break和continue语句

Example: Python break

for val in "string":
    if val == "i":
        break
    print(val)

print("The end")

 

Output

s
t
r
The end

In this program, we iterate through the "string" sequence. We check if the letter is "i", upon which we break from the loop. Hence, we see in our output that all the letters up till"i" gets printed. After that, the loop terminates.

 例子:Python break

for val in "srting":
    if val == "i":
        break
    print(val)
print("The end")

 输出

s
r
t
The end

在是个程序,我们通过"string"序列遍历。我们检查,如果字母是"i", 我们中断循环。

因此,我们可以看着我们的输出,直到字母"i"之上被打印。后面这些,循环终止。


Python continue statement

The continue statement is used to skip the rest of the code inside a loop for the current iteration only. Loop does not terminate but continues on with the next iteration.

continue语句

这继续语句用于使用跳过对于当前遍历的循环里面剩余的代码。循环不终止,但是下一次循环继续。


Syntax of Continue

Continue语法

continue

Flowchart of continue 

continue流程图

python基础入门----break和continue语句

The working of continue statement in for and while loop is shown below.

continue语句和while循环工作情况在下面展示。

python基础入门----break和continue语句

Example: Python continue

# Program to show the use of continue statement inside loops

for val in "string":
    if val == "i":
        continue
    print(val)

print("The end")

Output

s
t
r
n
g
The end

例子:python continue 

输出

[email protected]:~$ cat 1.py
for val in "srting":
    if val == "i":
        continue
    print(val)
print("The end")

[email protected]:~$ python3 1.py
s
r
t
n
g
The end

This program is same as the above example except the break statement has been replaced with continue.

We continue with the loop, if the string is "i", not executing the rest of the block. Hence, we see in our output that all the letters except "i" gets printed.

 这程序和上面的例子一样,除了break语句换成了continue语句。

我们继续循环,如果字符串是"i",剩余的模块不执行。因此,我们可以看到,我们的字母除了''i''都输出了。


Check out these examples to learn more: