1 Python基本数据类型
1.1 字符串str类型的处理
#str 转换成bool
print(bool(" "))
#字符串是有索引的
name='TracyMcGrady'
name_1=name[0]
print(name_1)
name_2=name[-1]
print(name_2)
#切片
name_1=name[0:5] #顾头不顾尾
print(name_1)
name_2=name[-7:]
print(name_2)
name_3=name[:5:2]
print(name_3)
#倒着取
name_4=name[-1:-8:-1]
print(name_4)
#颠倒字符串
name_5=name[-1::-1]
print(name_5)
name="TracyMcGrady"
print(name.capitalize()) #*只首字母大写
print(name.upper()) #全部大写
print(name.lower()) #全部小写
print(name.swapcase()) #*大小写翻转
print(name.title()) #首字母大写,非字母隔开的每个单词首字母大写
print(name.center(30,"*")) #居中,默认填充物是空格
print(name.startswith("Mc",5)) #以什么什么开头
print(name.endswith("y",-1)) #以什么什么结尾
name=" TracyMcGrady "
print(name.strip()) #***去重换行符号,
，登录的时候会用到
names="TracyMcGrady:Kobe:James"
print(names.split(":")) #***切割
print("+".join(names)) #把加号插入到每个字符中间
L1=["xiaojin","hujingjing","hanoeng"]
print("_".join(L1)) #把列表的值转换成字符串
name="TracyMcGrady"
print(name.replace("TracyMcGrady","James")) #***替换
#公共方法:
s="nikending不知道zheyouduochang"
print(len(s)) #多长
print(s.count("n")) #出现几次
#格式化输出format
res="My name is {0},I am born in {1},I like {2},My name is {0}".format("xiaojin",1995,"Basketball")
print(res)
'''
1,验证码不区分大小
2,登录的去除空格
'''
#输入验证码,不会区别大写小
code="AbCd"
your_code=input("your code >>:")
auth=your_code.upper()
code=code.upper()
if auth == code:
print("ok")
#登录去除收尾空格,制表符号
name=input("user>>:").strip()
print(name)
1.2 列表list的处理
'''
列表：
1,能储存大量的数据
2,切片
3,列表增删改查
'''
#增加
info=["a","c","d"]
info.append("e") #在后面增加
print(info)
info.insert(1,"b") #插入到1号索引位置
print(info)
info.extend(["f","g","h"]) #把迭代器的每个迭代对象逐个添加到列表里面
print(info)
#删除
print(info.pop(-1)) #按索引删除
print(info.remove("g")) #按元素删除
#info.clear() #清空列表,但在内存中,只是数据没有
#del info #从内存删除,能切片删除
print(info)
del info[-3:]
print(info)
#更改
info[1]="a" #按元素去改
print(info)
info[:3]=["q","w","e"] #按区域更改
print(len(info)) #查找列表有几个元素
L1=[9,8,7,6,5,4,3,2,1,3,4] #sort从小到大
L1.sort()
print(L1)
L1.sort(reverse=True) #颠倒
print(L1)
L1=[3,5,1,2,3,6]
L1.reverse() #直接颠倒不排序,相当于L2=L1[::-1]
print(L1)
#***列表的嵌套
L1=[1,2,"TracyMcGrady",[4,5,"kobe","肖进",77],"GoodBye"]
#将TracyMcGrady全部变成大写
#给[4,5,"肖进"]追加一个"胡婧婧"
#把kobe大写
#把77变成777
L1[2]=L1[2].upper()
print(L1)
L1[3].append("胡婧婧")
print(L1)
L1[3][2].title()
print(L1)
#L1[3][4]=str(L1[3][4])+"7"
#L1[3][4]=int(L1[3][4])+700
'''
漂亮的人的工资涨500
丑的人从的重列表中删除
'''
students=[
{"name":"肖进","age":23,"salary":5000,"is_pretty":True},
{"name":"胡婧婧","age":23,"salary":7000,"is_pretty":True},
{"name":"韩鹏","age":23,"salary":2000,"is_pretty":False},
]
count=-1
for student in students:
count=count+1
if student.get("is_pretty"):
student["salary"]=student.get("salary")+500
else:
del students[count]
print(students)
1.3 字典的数据处理
info={"name":"肖进","age":21,"is_cool":True}
#增改
info["high"]=180
info["name"]="韩鹏"
info["is_cool"]=False
info.setdefault("home","8511") #默认,如果有,则覆盖
print(info)
#删除
info.pop("age") #删除某个key
print(info.pop("{0}","没有此key{0}".format("age1"))) #防止报错
# print(info)
# info.clear() #清空字典
# del info["name"] #删除字典的某个key-value
# print(info)
#查询
print(info.get("name","没有此key"))
print(info.get("name1","没有此key"))
for key in info.keys():
print(key)
for value in info.values():
print(value)
for key,item in info.items():
print(key,item)
# fromkeys,多个key对应一个value
dic=dict.fromkeys("abc",[])
dic.get("a").append("cool")
print(dic)
#字典的覆盖
info1={"name":"xiaojin","age":23,"is_cool":True}
info2={"name":"hanpeng","sex":"man"}
#把字典1覆盖到字典2
info2.update(info1)
print(info1)
print(info2)
info={"name":"肖进",
"age":"23",
"home":"黑龙江",
"company":{
"name":"指掌易",
"salary":5000,
"work_time":"4个月",
"beautiful":True,
}
}
is_beautiful=info["company"]["beautiful"]
if is_beautiful:
pay_rise=info["company"]["salary"]
info["company"]["salary"]=pay_rise+500
print(info)
'''
None，0，空（空字符串，空列表，空字典等）三种情况下布尔值为False
'''
name_info={
"name_list":["Iverson","James","Kobe","TracyMcGrady"],
"TracyMcGrady":{
"age":36,
"born":1974,
"profession":"basketball",
"home":"usa",
}
}
#1,["Iverson","James","Kobe","TracyMcGrady"]追加一个元素，'Arlen'
#2，将Kobe全部变成大写。
#3, 将basketball首字母大写。
#3，将usa改成美国。
name_info.get("name_list",None).append("Arlen")
print(name_info)
name_info.get("name_list",None)[2]=name_info.get("name_list",None)[2].upper()
print(name_info)
name_info.get("TracyMcGrady")["profession"]=name_info.get("TracyMcGrady")["profession"].capitalize()
print(name_info)
name_info.get("TracyMcGrady")["home"]="美国"
print(name_info)
1.4 集合的处理
#集合
'''
无序
关系测试，交集，并集，子集，差集
去重(列表的去重)
'''
# set1={1,"alex",False,(1,2,3)}
# L1=[1,1,2,3,4,4,4,5,6,7]
# L2=set(L1)
# print(L2)
#交集
set1 = {1,2,3,4,5}
set2 = {4,5,6,7,8}
print(set1&set2)
#并集
print(set1|set2)
#差集
#set1独有的
print(set1-set2)
#反交集
print(set1^set2)
1.5 防错指南
'''
for 循环当中不要轻易去删除列表,字典中的值
因为删除会破坏索引,或者对应的key,使循环不完整，容易出错
'''
#列表删除值的方法
name_lists=["TracyMcGrady","Kobe","James","Iverson","Carter"]
#删除基数的索引
# 方法一:
del name_lists[1::2]
print(name_lists)
#方法二:颠倒列表索引
for i in range(len(name_lists)-1,-1,-1):
if i % 2 == 1:
del name_lists[i]
print(name_lists)
#删除字典里面带c并且不区分大小写
name_dict={
"TracyMcGrady":"火箭",
"Kobe":"湖人",
"James":"骑士",
"Carter":"小牛",
"Iverson":"费城76人",
}
list_name=[]
for name in name_dict:
name1=name.upper()
if "C" in name1:
list_name.append(name)
for l in list_name:
name_dict.pop(l,None)
print(name_dict)
1.6 深浅copy
#浅拷贝copy：
#对于浅copy来说,第一层创建的是新的内存地址,而从第二层开始,指向的都是同一个内存地址,
#所以,对于第二层以及更深的层数来说,保持一致性。
L1=[1,2,[1,2]]
L2=L1.copy()
L1[2].append(3)
print(id(L1),L1)
print(id(L2),L2)
L1.append(4)
#深拷贝deepcopy
import copy
L1=[1,2,[1,2]]
L2=copy.deepcopy(L1)
L1[2].append(3)
print(id(L1),L1)
print(id(L2),L2)