# 三、lsit 生成式（列表生成式）

## 1、创建 list 的方式

``````# -*- coding: UTF-8 -*-

list1=list ( range (1,31) )
print(list1)
``````

``````[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30]
``````

``````print('\n'.join([' '.join ('%dx%d=%2d' % (x,y,x*y)  for x in range(1,y+1)) for y in range(1,10)]))
``````

``````1x1= 1
1x2= 2 2x2= 4
1x3= 3 2x3= 6 3x3= 9
1x4= 4 2x4= 8 3x4=12 4x4=16
1x5= 5 2x5=10 3x5=15 4x5=20 5x5=25
1x6= 6 2x6=12 3x6=18 4x6=24 5x6=30 6x6=36
1x7= 7 2x7=14 3x7=21 4x7=28 5x7=35 6x7=42 7x7=49
1x8= 8 2x8=16 3x8=24 4x8=32 5x8=40 6x8=48 7x8=56 8x8=64
1x9= 9 2x9=18 3x9=27 4x9=36 5x9=45 6x9=54 7x9=63 8x9=72 9x9=81
``````

## 2、list 生成式的创建

``````[expr for iter_var in iterable]
[expr for iter_var in iterable if cond_expr]
``````

``````# -*- coding: UTF-8 -*-
lsit1=[x * x for x in range(1, 11)]
print(lsit1)
``````

``````[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
``````

``````# -*- coding: UTF-8 -*-
lsit1= [x * x for x in range(1, 11) if x % 2 == 0]
print(lsit1)
``````

``````[4, 16, 36, 64, 100]
``````

``````# -*- coding: UTF-8 -*-
lsit1= [(x+1,y+1) for x in range(3) for y in range(5)]
print(lsit1)
``````

``````[(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5)]
``````