while循环 aa = 100 bb = 0 cc = 1 while cc <= aa: bb = bb + cc cc += 1 print("1 到 %d 之和为:%d" % (aa, bb)) n = 100 sum = 0 counter = 1 while counter <= n: sum = sum + counter counter += 1 print("1 到 %d 之和为: %d" % (n, sum)) 无限循环 a = 1 while a ==1: b = int(input("请输入一个数字>>>")) print("你输入的数字是>>>",b) print("good bye!") while 循环使用else语句 count = 0 while count < 5: print(count,"小于5") count = count + 1 else: print(count,"大于5") range函数 for i in range(10): print("i",i) for s in range(5,10): print("s:",s) break和continue语句及循环else子句 for wo in "long": if wo == "li": break print("当前的字母是>>>",wo) a = 100 while a > 0: print("当前变量为>>>",a) a = a - 5 if a == 4: break print("good bye !") continue语句用来告诉python跳过当前循环语句块中的语句进行下一个循环 for wo in "long": if wo == "o": continue print("当前的字母是>>>",wo) a = 100 while a > 0: a = a -5 if a == 0: continue print("当前的变量为>>>",a) 循环语句可以有else子句,它在穷尽列表(以for循环)或条件变为false(以while循环)导致循环终止时被执行 但循环被break终止时不执行 for n in range(2,10): for x in range(2,n): if n % x == 0: print(n,"等于",x,"*", n //x ) break else: print(n,"是质数") pass 语句是空语句,是为了保持程序结构的完整性 for wo in "long": if wo == "o": pass print("执行pass快") print("当前字母>>>",wo)