python 2

#奇数和
# i =1
# sum = 0
# while i <= 100:
#     sum = sum +i
#     i = i+2
# print(sum)

#偶数和
# i = 0
# sum = 0
# while i<=100:
#     sum = sum + i
#     i = i+2
# print(sum)

# 奇数减偶数
# i = 0
# t1 = 0
# t2 = 0
# t3 = t2-t1
# while i<=100:
#     if i%2 == 0:
#         t1 = t1+i
#     else:
#         t2 = t2+i
#     i = i+1
#     t3 = t2 - t1
# print(t3)

# for i in range(10,0,-3):
#     print(i , end = ' ')


#for循环遍历字符串
#方法1
# str1 = 'chengang'
# for i in str1:
#     print(i,str1.index(i))
#     print('%s对应的索引为%d'%(i,str1.index(i)))


#方法2
# str1 = 'chengang'
# list1 = list(str1)
# # print(list1)
# for i in range(len(list1)):
#     # print(list1[i],i)
#     print('%s对应的索引值为%d'%(list1[i],i))

#continue语句
# for i in range(10):
#     if i == 5:
#         continue
#     print(i)

#break语句
# for i in range(10):
#     if i == 5:
#         break
#     print(i)