九九乘法表练习： (while/for循环嵌套，break结束循环，range()函数生成取头不取尾的整数)

九九乘法表

for循环

for i in range (1,10):
    for a in range(1,10):a
        print('%d X %d = %d' % (a,i,i*a),end = '  ')
        if i==a:
            print('')
            break

while循环

i = 1
while i <= 9:
    j = 1
    while j <= i:
        print('%d X %d = %d' % (j,i,i*j),end = '  ') 
        j += 1
    print('')
    i += 1

print()函数里有个参数’end’是用来控制换行行数和结尾字符

print(‘hello’,end=’’)
print(‘world’)
#》》helloworld

print(‘hello’,end=’ ')
print(‘world’)
#》》hello world

print(‘hello’,end=’!’)
print(‘world’)
#》》hello!world