列表6,7

1.列表6

#l列表推导式
oho=[1,2,3]
for i in range(len(oho)):
    oho[i]=oho[i]*2
print(oho)#[2, 4, 6]
#推导式[变量 for 变量 in 循环次数]
#最终导入的值是推导式中的第一个变量即i*2
oho=[i*2 for i in oho]
print(oho)#[4, 8, 12]
x=[i for i in range(5)]
print(x)#[0, 1, 2, 3, 4]
x=[i*2 for i in range(5)]
print(x)#[0, 2, 4, 6, 8]最后的值在于i*2
#将值导入空列表
x=[]
for i in range(5):
    x.append(i+1)
print(x)#[1, 2, 3, 4, 5]
#字符串
y=[i*2 for i in "你好"]
print(y)#['你你', '好好']
#将字符转换为对应的ascll码值（ord()）
code=[ord(c) for c in "HOLLOa"]
print(code)#[72, 79, 76, 76, 79, 97]
#二维列表
mat=[
    [1,2,3],
    [4,5,6],
    [7,8,9]]
#获取二维列表的行
cod=[row[1] for row in mat]
print(cod)#[2, 5, 8]
#列表对角线上元素
dia=[mat[i][i] for i in range(len(mat))]
print(dia)#[1, 5, 9]
dia2=[mat[i][2-i] for i in range(len(mat))]
print(dia2)
print(len(mat))

2.列表7

# 列表7
# 推导式2
s = [[0] * 3] * 3
print(s)  # [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
s[1][1] = 1
print(s)  # [[0, 1, 0], [0, 1, 0], [0, 1, 0]]
# 这个是引用列表，所以改变的是二维中的每一行[1]的值
# 创建二维列表
A = [0] * 3
for i in range(3):
    A[i] = [0] * 3
print(A)  # [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
A[1][1] = 1
print(A)  # [[0, 0, 0], [0, 1, 0], [0, 0, 0]]
S = [[0] * 3 for i in range(3)]
S[1][1] = 1
print(S)  # [[0, 0, 0], [0, 1, 0], [0, 0, 0]]
# 推导式2
even = [i for i in range(10) if i % 2 == 0]
print(even)  # [0, 2, 4, 6, 8]
w = ["ze", "shan", "zhen"]
W = [i for i in w if i[0] == "z"]
print(W)  # ['ze', 'zhen']
# 嵌套列表推导式
mat = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
zk = [lie for row in mat for lie in row]
print(zk)  # [1, 2, 3, 4, 5, 6, 7, 8, 9]
# 套娃添加
mk = []
for row in mat:
    for lie in row:
        mk.append(lie)
print(mk)  # [1, 2, 3, 4, 5, 6, 7, 8, 9]
d = [x + y for x in "fince" for y in "nihao"]
print(d)#['fn', 'fi', 'fh', 'fa', 'fo', 'in', 'ii', 'ih', 'ia', 'io', 'nn',
# 'ni', 'nh', 'na', 'no', 'cn', 'ci', 'ch', 'ca', 'co', 'en', 'ei', 'eh', 'ea', 'eo']
#将0-10之间偶数与能被三整除的数组成列表
b=[[x,y] for x in range(10) if x%2==0 for y in range(10) if y%3==0]
print(b)
#[[0, 0], [0, 3], [0, 6], [0, 9], [2, 0], [2, 3], [2, 6], [2, 9], [4, 0],
#  [4, 3], [4, 6], [4, 9], [6, 0], [6, 3], [6, 6], [6, 9], [8, 0], [8, 3], [8, 6], [8, 9]]