举例详解Python中循环语句的嵌套使用
Python编程语言允许在一个循环内嵌套另一个循环。下面将介绍几个例子来说明这一概念。
语法
在Python中嵌套循环语句的语法如下：
for iterating_var in sequence: for iterating_var in sequence: statements(s) statements(s)
Python编程语言允许在一个循环内嵌套另一个循环。下面将介绍几个例子来说明这一概念。
语法
在Python中嵌套循环语句的语法如下：
for iterating_var in sequence: for iterating_var in sequence: statements(s) statements(s)
Python编程语言的一个嵌套while循环语句的语法，如下所示：
while expression: while expression: statement(s) statement(s)
在循环嵌套最后需要说明的是，可以把任何类型的循环的任何其他类型的循环里面。例如，for循环内可以放置while循环，反之亦然。
例子
下面的程序使用一个嵌套的循环，从2到100中找出所有的素数：
#!/usr/bin/python i = 2 while(i < 100): j = 2 while(j <= (i/j)): if not(i%j): break j = j + 1 if (j > i/j) : print i, " is prime" i = i + 1 print "Good bye!"
当执行上面的代码，它会产生以下结果：
2 is prime 3 is prime 5 is prime 7 is prime 11 is prime 13 is prime 17 is prime 19 is prime 23 is prime 29 is prime 31 is prime 37 is prime 41 is prime 43 is prime 47 is prime 53 is prime 59 is prime 61 is prime 67 is prime 71 is prime 73 is prime 79 is prime 83 is prime 89 is prime 97 is prime Good bye!