Python基础

Posted 2021-03-26 素心~

# 列表类似JS中的数组
lst = [1,2,3,4,5]
# 列表常用的一些API
lst.append(6)

# 类比JS中的push，在列表后面追加一项元素

lst.insert(1,‘xiaT‘)

print(lst)

# 在索引为1的位置添加元素

lst2 = [1,2,3]
lst3 = [4,5,6]
lst2.extend(lst3)
print(lst2)
# 这个是迭代添加


lst4 = [1,2,3]
lst4.pop()
print(lst4)
# 删除最后一项,也可以制定索引删除会返回删除项

lst = ["UZI","XIAOHU","MLXG","MING"]
result = lst.remove("UZI")
print(result)
print(lst)

#  removeAPI返回的是None它内部实现没有做对象返回这里是单删除指定元素

lst.clear()
print(lst)
# 这个就不多说了清空


lst = ["UZI","XIAOHU","MLXG","MING"]
del lst[1:3:2]
print(lst)

# # 这里是切片删除步长2的情况下只能切掉XIAOHU



# # 下面介绍下修改
lst = ["UZI","XIAOHU","MLXG","MING"]
lst[0:3:2] = ["SMLZ","FAKER"]
print(lst)
# # 也可以使用步长迭代修改,但要注意的是如果元素个数对不上会报错

lst = ["UZI","XIAOHU","MLXG","MING"]
lst[0:1] = "简单实用的方法试试"
print(lst)
# [‘xe7‘, ‘xae‘, ‘x80‘, ‘xe5‘, ‘x8d‘, ‘x95‘, ‘xe5‘, ‘xae‘, ‘x9e‘, ‘xe7‘, ‘x94‘, ‘xa8‘, ‘xe7‘, ‘x9a‘, ‘x84‘, ‘xe6‘, ‘x96‘, ‘xb9‘, ‘xe6‘, ‘xb3‘, ‘x95‘, ‘xe8‘, ‘xaf‘, ‘x95‘, ‘xe8‘, ‘xaf‘, ‘x95‘, ‘XIAOHU‘, ‘MLXG‘, ‘MING‘]
# 返回的是这堆东西,我这里是utf-8的字节码,正常是汉字,也就他将字符串迭代扩展到了0的位置


lst = ["UZI","XIAOHU","MLXG","MING"]
lst[0:1:2] = [1,2,3,4,5,6]
print(lst)
# 我们发现数组也是同理但添加步长后就必须一一对应否则报错,字符串也是同理

# # 其他操作
lst = ["UZI","UZI","XIAOHU","MLXG","MING"]
num = lst.count("UZI")
print(num)
# # 查询UZI出现的次数
#
lst = [8,7,6,1,2,3,45]
lst.sort()
print(lst)
lst.sort(reverse=True)
print(lst)
# # 这个跟JS差不多升序降序排列
#
lst = ["UZI","UZI","XIAOHU","MLXG","MING"]
lst.reverse()
print(lst)
# # 反转很简单