for循环的使用实现99乘法表

For循环语法：

For i in range(start,end,step)

Print(i)

# for循环语句
# 输出1到9
for i in range(1,10):
    print(i)

# 输出0到9
for i in range(10):
    print(i)

print("------------------------------")
# 输出1到1,3,5,7,9
for i in range(1,10,2):
    print(i)

print("------------------------------")
# 输出1到0,2,4,6,8
for i in range(0,10,2):
    print(i)

print("------------------------------")
# 倒序打印输出9,7,5,3,1
for i in range(9,0,-2):
    print(i)

需求：使用for循环打印99乘法表，然后反转乘法表

# 使用for循环打印99乘法表
for i in range(1,10):
    for j in range(1,i+1):
        print("%d * %d = %d" % (j, i, j * i),end="\t")
    print()

print("------------------------------")
# 反转乘法表
for i in range(1,10).__reversed__():
    for j in range(1,i+1):
        print("%d * %d = %d" % (j, i, j * i),end="\t")
    print()

print("------------------------------")
for i in range(9,0,-1):
    for j in range(1,i+1):
        print("%d * %d = %d" % (j, i, j * i),end="\t")
    print()

break与continue的使用

Break：中断当前所在整个循环

Continue：中断当前循环，继续下一次循环

# Break：中断当前所在整个循环
# 输出0,1,2
for i in range(6):
    if(i==3):
        break
    print(i)

print("----------------")
# Continue：中断当前循环，继续下一次循环
# 输出0,1,2,4,5
for i in range(6):
    if(i==3):
        continue
    print(i)

使用嵌套循环打印菱形操作

需求：打印菱形

#半个打印菱形
line = 6
for i in range(0,line):
    # 打印每一行中的" "
    for k in range(line-i):
        print(" ",end="")
    # 打印每一行中的"*"
    for j in range(2*i+1):
        print("*",end="")
    print()

# print("---------------------------------")
line = 5
for i in range(0,line).__reversed__():
    # 打印每一行中的" "
    for k in range(line-i+1):
        print(" ",end="")
    # 打印每一行中的"*"
    for j in range(2*i+1):
        print("*",end="")
    print()

# line = 5
# for i in range(0,line):
#     # 打印每一行中的" "
#     for k in range(i+2):
#         print(" ",end="")
#     # 打印每一行中的"*"
#     for j in range(2*(line-i)-1):
#         print("*",end="")
#     print()

over......