python_9_for

#1
for i in range(10):#默认从0开始，步长为1
    print("loop",i)
#2
for i in range(0,10,1):#步长为1
    print("loop",i)
#3
for i in range(0,10,2):#步长为2
    print("loop",i)
# 3
for i in range(0,10,3):#步长为3
    print("loop", i)
# 4
for i in range(2,12,3):#从2到11，步长为,3
    print("loop", i)