python【while嵌套练习（*，乘法表）】

在控制台连续输出五行*,每一行星号数量一次递增

*
**
***
****
*****

*****
****
***
**
*

    *
   **
  ***
 ****
*****

*****
 ****
  ***
   **
    *

"""
#_*_coding:utf-8_*_
Name:无重复三位数.py
Date:1/17/19
Author:
Connect:[email protected]
Desc:
"""
row=1
while row<=5:
    col=1
    while col<=row:
        print('*',end='')
        col+=1
    print('')
    row+=1

row1=1
while row1<=5:
    col1=1
    while col1<=5-row1+1:
        print('*',end='')
        col1+=1
    print('')
    row1+=1

row3=1
while row3<=5:
    kong1=1
    while kong1<=5-row3:
        print(" ",end='')
        kong1+=1
    col3=1
    while col3<=row3:
        print('*',end='')
        col3+=1
    print('')
    row3+=1

row2=1
while row2<=5:
    kong=1
    while kong<row2:
        print(" ",end='')
        kong+=1
    col2=1
    while col2<=5-row2+1:
        print('*',end='')
        col2+=1
    print('')
    row2+=1

乘法表打印（正着打印，反着打印）

分别四种情况
a=1
while a<=9:
     b=1
     while b<=a:
         print('%dx%d=%d\t'%(a,b,a*b),end='')
         b+=1
     a+=1
     print('')
     
a=9
while a>=0:
     b=1
     while b<=a:
         print('%dx%d=%d\t'%(a,b,a*b),end='')
         b+=1
     a-=1
     print('')

a=1
while a<=9:
     c=1
     while c<=9-a:
        print("\t\t",end=' ')
        c+=1
     b=1
     while b<=a:
        print('%dx%d=%d\t'%(a,b,a*b),end='')
        b+=1
     a+=1
     print('')

a=9
while a>=0:
     c=1
     while c<=9-a:
         print("\t\t\t",end='' )
         c+=1
     b=1
     while b<=a:
         print('%dx%d=%d\t'%(a,b,a*b),end='')
         b+=1
     a-=1
     print('')

分别四种情况