1、 迭代式循环:for,语法如下
for i in range(10):
for i in range(1,10): for j in range(1,i+1): print('%s*%s=%s' %(i,j,i*j),end=' ') print()
2、break与continue(同while)
nums = [11, 22, 33, 44, 55] for x in nums: if x == 22 or x == 44: continue print(x)
nums = [11, 22, 33, 44, 55] for x in nums: if x == 44: break print(x)
3、循环嵌套 for + for
for i in range(3): for j in range(4): print(i,j) 0 0 0 1 0 2 0 3 1 0 1 1 1 2 1 3 2 0 2 1 2 2 2 3
for i in range(1,10): for j in range(1,i+1): print('%s*%s=%s' %(i,j,i*j),end=' ') print()
#分析 ''' #max_level=5 * #current_level=1,空格数=4,*号数=1 *** #current_level=2,空格数=3,*号数=3 ***** #current_level=3,空格数=2,*号数=5 ******* #current_level=4,空格数=1,*号数=7 ********* #current_level=5,空格数=0,*号数=9 #数学表达式 空格数=max_level-current_level *号数=2*current_level-1 ''' #实现 max_level=5 for current_level in range(1,max_level+1): for i in range(max_level-current_level): print(' ',end='') #在一行中连续打印多个空格 for j in range(2*current_level-1): print('*',end='') #在一行中连续打印多个空格 print()
4、for +else
names = ['egon', 'kevin1111_dsb', 'alex_dsb', 'mac_dsb'] for name in names: if name == 'kevin_dsb': break print(name) else: print('======>')
5、for + range range的用法 range(1,5,1)结果为[1,2,3,4] 取头不顾尾默认后面的1为步长,默认步长为1,可以不写
range的用法 range(1,5) [1, 2, 3, 4] for i in range(1,5): print(i) 1 2 3 4 >>> range(1,5,1) [1, 2, 3, 4] >>> range(1,5,2) # 1 3 [1, 3]