Python基础(4)——数组&元组

list = [1,2,3,4,5]
list = [1,False,"string"]

list =['a','b','c','d']
for i in list:
    print(i)

list =['1','2','3','4']
print(len(list))
print(list[1])
print(list[-1])

list = ["1","2","3","4","5"]
print(list[2:4])
print(list[:3])
print(list[3:])
#['3', '4']
#['1', '2', '3']
#['4', '5']

list = [1,2,3]
print(list)
list.append(4)
print(list)

alist = [2,3,4]
alist.insert(0,1)
print(alist)
# [1, 2, 3, 4]

li = [1,2,4,5]
li.extend([0,8])
print(li)
# [1, 2, 4, 5, 0, 8]

alist = [1,2,3,4]
alist.pop(2)
print(alist)
[1, 2, 4]

alist = [1,2,3,4]
alist.remove(3)
print(alist)

alist = [1,2,3,4]
if 3 in alist:
    print("存在数据3")

li = [1,2,3,4,5]
li.clear()
print(li)
# []

li = [2,1,6,4,5,3]
li.sort()
print(li)
#[1, 2, 3, 4, 5, 6]

li = [1,2,3,4,5]
li.reverse()
print(li)
# [5, 4, 3, 2, 1]

result = []
for i in range(1, 10):
    if i % 2 == 0:
        result.append(i * i)
print(result)

r = [i * i for i in range(1, 10) if i % 2 == 0]
print(r)

from random import randint

result = [randint(0, 20) for _ in range(10)]
print(result)
r = [x for x in result if x % 2 == 0]
print(r)

aTuple = (1,2,3)
# 元组数据无法修改
aTuple[2] = 4
# TypeError: 'tuple' object does not support item assignment

tu = (1)
print(type(tu))
tu =(1,)
print(type(tu))
# <class 'int'>
# <class 'tuple'>

tu =(1,2,4,5,6)
print(list(tu))#元组转为数组
li =[1,2,3,4,5]
print(tuple(li))#数组转为元组
# [1, 2, 4, 5, 6]
# (1, 2, 3, 4, 5)