python-第一块，笔记整理和学习内容复习（day4 - day5 - day6）
DAY4
学习内容
今天主要还是学习字典和集合的操作。根据这几天的学习写了第一次的作业--三级菜单
city_info = {
'湖北':{'武汉':['武昌','汉口','汉阳'],'黄冈':['蕲春','罗田','英山','黄梅'],'荆州':['公安','石首','沙市']},
'安徽':{'合肥':['肥西','庐阳','蜀山'],'芜湖':['三山','鸠江','镜湖','弋江'],'安庆':['桐城','潜山','太湖']},
'江苏':{'南京':['建邺','雨花台','秦淮'],'苏州':['吴中','相城','平江','沧浪'],'无锡':['梁溪','滨湖','锡山']}
}
def open_meau:
exit_flag = False
while not exit_flag:
for i in city_info:
print(i)
choose1 = input("please input your choosen1>>> ")
if choose1 in city_info:
while not exit_flag:
for j in city_info[choose1]:
print("\t",j)
choose2 = input("please input your choosen2>>> ")
if choose2 in city_info[choose1]:
#while True:
for k in city_info[choose1][choose2]:
print("\t\t",k)
choose_exit = input("This is the bottom,b to return to a layer>>>")
if choose_exit == "b":
pass
elif choose_exit =="q":
exit_flag = True
elif choose2 == "b":
break
elif choose2 == "q":
exit_flag = True
else:
print("your input was wrong,please input again")
elif choose1 == "q":
exit_flag = True
else:
print("your input was wrong,please input again")
随后更新了最新版
import yaml #导入yaml模块
f = open('city_info',"rb")
dict_city = yaml.load(f) #利用yaml模块将城市信息文件转为多级字典
f.close()
exit_flag = False #定义程序退出信息
while not exit_flag:
for i in dict_city: #打印第一级城市信息
print(i)
choose1 = input("please input your choosen1>>> ") #输入第二层城市选择
if choose1 in dict_city:
while not exit_flag:
for j in dict_city[choose1]: #打印第二层城市信息
print("\t",j)
choose2 = input("please input your choosen2>>> ") #输入第三层城市选择
if choose2 in dict_city[choose1]:
while not exit_flag:
for k in dict_city[choose1][choose2]: #打印第三层城市信息
print("\t\t",k)
choose3 =input("please input your choosen3>>> ") #输入第四层城市信息选择
if choose3 in dict_city[choose1][choose2]:
for m in dict_city[choose1][choose2][choose3]: #打印第四层城市信息
print("\t\t\t",m)
choose_exit = input("This is the bottom,b to return to a layer>>>") #打印菜单最底层信息
if choose_exit == "b": #返回上一层
pass
elif choose_exit =="q": #退出程序
exit_flag = True
elif choose3 =="b": #返回上一层
break
elif choose3 =="q": #退出程序
exit_flag = True
else:
print("your input was wrong,please input again")
elif choose2 == "b": #返回上一层
break
elif choose2 == "q": #退出程序
exit_flag = True
else:
print("your input was wrong,please input again")
elif choose1 == "q": #退出程序
exit_flag = True
else:
print("your input was wrong,please input again") #输入信息有误
笔记
集合
1、 .isdisjoint() #判断有无交集
2、 .add() #添加一项
.updata[] #添加多项
3、 .remove(" ") #删除
.discard(" ") #如果删除值不在，返回none 不会报错
.pop( ) #随机删除
list_1 = [1,4,5,7,3,6,7,9]
list_1 = set(list_1)
list_2 = set([2,6,0,66,22,8,4])
print(list_1,list_2,type(list_1))
#交集
list_1.intersection(list_2)
print(list_1.intersection(list_2))
print(list_1 & list_2)
print("---------------------")
#并集
print(list_1.union(list_2))
print(list_1 | list_2)
print("---------------------")
#差集
print(list_1.difference(list_2))
print(list_1 - list_2)
print(list_2.difference(list_1))
print(list_2 - list_1)
print("---------------------")
#对称差集
print(list_1.symmetric_difference(list_2))
print(list_1 ^ list_2)
print("---------------------")
#子集
print(list_1.issubset(list_2))
print(list_1.issuperset(list_2))
DAY5
学习内容
今天学习的主要是函数，写了一系列代码
def func1():
print("This is the func1")
return 0
def func2():
print("This is the func2")
def func3():
print("This is the func3")
return 1,"hubei",["wa","jionu"],{"name":"zd"}
x=func1()
y=func2()
z=func3()
print(x)
print(y)
print(z)
全局变量和局部变量
school = "武汉轻工大学"
def change_name(name):
global school
school = "湖北大学"
print(name,school)
change_name('董政宽')
递归
def clu(number):
if int(number/2)>0:
print(number)
return clu(int(number/2))
clu(10)
DAY6
学习内容
今天学习了文件的一系列操作，有文件的读、写、追加等，详见代码
文件的读
f = open("today1","r+",encoding="utf-8")
#list_f = f.readlines()
#print(list_f)
print(f.readline())
print(f.readline())
f.write("\n我爱北京天安门")
f.write("\n北京天安门最伟大")
f.flush()
f.write("\n你好")
for line in f.readlines():
print(line.strip())
for index,line in enumerate(f.readlines()): #不好的写法，只适于小文件，大文件不适用
if index == 1:
print("----------------")
print(line.strip())
count = 0
for line in f:
if count == 2:
print("--------------")
count +=1
print(line.strip()) #高逼格写法，读一行，存一行
count += 1
文件的修改
f = open("today1","r",encoding="utf-8")
f_new = open("today1_new","w",encoding="utf-8")
for line in f:
if "你好"in line:
line = line.replace("你好","hello world")
f_new.write(line)
f.close()
f_new.close() #修改文件代码
笔记
1、读 f = open("文件名","r")
f.read
2、写 f = open("文件名","w")
f.write("内容,\n")
3、关闭 f.close()
4、读一行 f.readline()
5、读出列表 f.readlines()
6、r+：读写模式
a：追加模式
a+：追加读
w+：写读，先创建文件再写
7、f.tell() #改变光标的位子
8、f.seek() #光标回到某个位子，默认是0
9、f.flush() #实时刷新
10、f.truncate() #不写，文件清空；写，从写的位子截断
11、with open("文件名") as f: #打开不用关闭，自动随程序关闭保存，可同时打开多个文件。
编码
python2.7 默认解码是bytes
python3.0 默认解码是unicode
unciode 万国编码，包含utf-8和gbk等
utf-8 可变长的编码扩展集，所以英文按ASCII存储占一个字节；所以中文占3个字节
