课后练习：求1-100的所有数的和
（1）while循环
1 #!/usr/bin/env python 2 #-*- coding:utf-8 -*- 3 n = 1 4 sum = 0 5 while n < 101: 6 print(n) 7 sum = sum + n 8 n = n + 1 9 print(sum)
（2）for循环
1 #!/usr/bin/env python 2 #-*- coding:utf-8 -*- 3 sum = 0 4 for a in range(1,101,1): 5 sum = sum + a 6 print(sum)
1 #!/usr/bin/env python 2 #-*- coding:utf-8 -*- 3 sum = 0 4 for a in range(1,101,1): 5 sum = sum + a 6 print(a) 7 print(sum)
执行结果：
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Process finished with exit code 0
