day07-Python运维开发基础(深/浅拷贝、字典/集合/相关操作)

1. 深拷贝与浅拷贝

# ### 深拷贝 和 浅拷贝
"""
a = 7
b = a
a = 8
print(b)

lst1 = [1,2,3]
lst2 = lst1
lst1.append(4)
print(lst2)day
"""
# 浅拷贝 copy模块中有一个同名方法也叫copy
# 方法一 (推荐)
"""
import copy 
lst1 = [1,2,3]
lst2 = copy.copy(lst1)
lst1.append(4)
print(lst2)
"""
# 方法二
# 列表.copy
lst1 = [1,2,3]
lst2 = lst1.copy()
lst1.append(5)
print(lst1)
print(lst2)

# 深拷贝 copy模块中有一个方法叫deepcopy
"""
# 浅拷贝只能复制列表中的一级所有元素,二级或者多级中的元素无法复制,所以引出深拷贝
lst1 = [1,2,3,[4,5,6,7]]
lst2 = lst1.copy()
lst1[-1].append(7)
print(lst2)
"""
import copy
lst1 = [1,2,3,[4,5,6]]
lst2 = copy.deepcopy(lst1)
lst1[-1].append(9)
print(lst2)


# 深拷贝字典
dic1 = {"a":1 , "b":[1,2,3]}
dic2 = copy.deepcopy(dic1)
dic1["b"].insert(2,4)
print(dic2)
print(dic1)


# 深拷贝 比 浅拷贝 占用的空间更大,速度稍慢;
# 多级容器用深拷贝, 一级容器用浅拷贝

深拷贝与浅拷贝 示例代码

2. 字典相关函数

# ### 字典相关函数
dic = {}
# "top":"the shy","middle":"faker","bottom":"uzi","support":"rookie","jungle":"厂长"
# 增
dic["top"] = "the shy"
dic["middle"] = "faker"
dic["bottom"] = "uzi"
dic["support"] = "mata"
dic["jungle"] = "kakao"
print(dic)

#fromkeys()  使用一组键和默认值创建字典 (为当前键赋初始值,不推荐) 
lst = ["top","middle","bottom"]
dic = {}.fromkeys(lst,None)
print(dic)

# 注意点(列表)
lst = ["top","middle","bottom"]
dic = {}.fromkeys(lst,[])
print(dic)
dic["top"].append(1)
print(dic)

# 删
dic = {'top': 'the shy', 'middle': '西门', 'bottom': 'uzi', 'support': 'mata', 'jungle': 'kakao'}
#pop()       通过键去删除键值对 (若没有该键可设置默认值,预防报错)
# res = dic.pop("middle")
# print(dic)
# print(res)

mykey = "jungle123"
res = dic.pop(mykey,"该键不存在")
print(res  ,  dic)

#popitem()   删除最后一个键值对 
res = dic.popitem()
print(res)
print(dic)

#clear()  清空字典
dic.clear()
print(dic)

# 改
#update() 批量更新(有该键就更新,没该键就添加)
dic = {"ldb":"吕洞宾","lch":"蓝采和","tgl":"忒乖离","zgl":"张果老","xboyww":"神秘男孩"}
dicnew = {"hxg":"何仙姑","xboyww":"王文"}
dic.update(dicnew)
print(dic)

# 查
#get()    通过键获取值(若没有该键可设置默认值,预防报错) 
dic = {"ldb":"吕洞宾","lch":"蓝采和","tgl":"忒乖离","zgl":"张果老","xboyww":"神秘男孩"}
# print(dic["xboyww1111111"]) # 如果正常进行获取,当键不存在时直接报错
print(dic.get("xboyww1111111","该键不存在")) # get方法可以在不存在这个键时,设置默认值,不报错


dic = {"ldb":"吕洞宾","lch":"蓝采和","tgl":"忒乖离","zgl":"张果老","xboyww":"神秘男孩"}
#keys()   将字典的键组成新的可迭代对象
res = dic.keys()
print(res)

#values() 将字典中的值组成新的可迭代对象
res = dic.values()
print(res)

#items()  将字典的键值对凑成一个个元组,组成新的可迭代对象
res = dic.items()
print(res) 

字典相关函数 示例代码

day07