数据类型拾遗

 

 

#UTF编码，一个汉字对应三个字符

py2.7 字节循环

py3.5 字符循环

#==============================================================================
# #字符串转字符
# name = "李露"
# for i in name:
# print(i)
# byte_list = bytes(i,encoding="utf8")
# print(byte_list)
# for b in byte_list:
# print(b,bin(b))
# 
# 
#==============================================================================

#==============================================================================
# # #字节转回字符串
# name = "李露"
# for i in name:
# print(i)
# byte_list = bytes(i,encoding="utf8")
# print(byte_list)
# new1 = str(byte_list,encoding="utf8")
# print(new1)
# 
# 
#==============================================================================

#字符串转换成列表
# s1 = "李露"
# s2 = list(s1)
# print(s2)
#==============================================================================
# 
# #元组转化成列表
# t1 = ("al","ba","qi")
# t2 = list(t1)
# print(t2)
#==============================================================================

#字典转化成列表(可以互相转换)
# dict1 = {
# "name":"alex",
# "age":19,
# }
# dict2 = dict1.items()
# dict3 = list(dict2)
# print(dict3)

# #列表转字典
# s1 = dict(dict3)
# print(s1)

#
# li = ['alex',12,23]
# temp =("as","qw","ed")
# li.extend(temp)
# li.reverse()
# print(li)
# li.insert(2,"asd")
# print(li)

#==============================================================================
# li = ['alex',12,23]
# q1 = li[1:2]
# print(q1)
# 
#==============================================================================

#列表里面嵌套字典，索引取value值

#
# li = ['alex',12,{'a':12,'w':{'d':21,'df':23}}]
# print(li[2]['w']['df'])
#

##############元组############################################################

#count
# t = (11,22,33,44,550)
# print(t.count(11))

#嵌套（元素不可修改）###元组元素本身不可修改，但嵌套后元素的元素可以修改

# t = (11,22,33,['qw',12,'de'],23)
# t[3].append(12)
# print(t)
#
#

#
# dict = {'k1':'we','de':'ey'}
# dict['ke'] = "wfr"
# print(dict)
# dict.update({"ge":13})
# print(dict)
#
# ########创建 'k1',若存在此key则更新此对应value；若不存在，则新增此键值对。
# dict['k1'] = 23
# print(dict)
#
#


#==============================================================================
# dic = {'k1':12,'k2':34}
# 
# n1 = dict.fromkeys(["k1","k2","k3"],2)
# print(n1)
#==============================================================================
#==============================================================================
# 
# s1 = [12,12,34]
# 
# dict_1 = dict(enumerate(s1,10))
# print(dict_1)
# 
# 
#==============================================================================


#######一般的，1）对于str，执行功能，产生新的内容
# 2）对于list、tuple、dict 而言，执行功能，只在原内容上进行修改。


# list_1 = list(range(100))
# list_2 = []
# list_3 = []
#
# for i in list_1:
# if i <= 66:
# list_2.append(i)
# elif i>66:
# list_3.append(i)
# dict_1={'k1':[],'k2':[]}
# dict_1['k1']=list_2
# dict_1['k2']=list_3
# print(dict_1)


'''
二、查找

查找列表中元素，移除每个元素的空格，并查找以 a或A开头 并且以 c 结尾的所有元素。

li = ["alec", " aric", "Alex", "Tony", "rain"]

tu = ("alec", " aric", "Alex", "Tony", "rain")

dic = {'k1': "alex", 'k2': ' aric', "k3": "Alex", "k4": "Tony"}
'''
#
# li = ["alec", " aric", "Alex", "Tony", "rain"]
#
# for i in li:
# b = i.strip()
# if b.startswith("a") or b.startswith("A") and b.endswith("c"):
# print(b)
#

#
# tu = ("alec", " aric", "Alex", "Tony", "rain")
#
# for i in tu:
# b = i.strip()
# if b.startswith("a") or b.startswith("A") and b.endswith("c"):
# print(b)
#
#
#
#
# dic = {'k1': "alex", 'k2': ' aric', "k3": "Alex", "k4": "Tony"}
#
# for i in dic.values():
# b = i.strip()
# if b.startswith("a") or b.startswith("A") and b.endswith("c"):
# print(b)


'''
三、输出商品列表，用户输入序号，显示用户选中的商品

商品 li = ["手机", "电脑", '鼠标垫', '游艇']
'''
'''
li = ["手机", "电脑", '鼠标垫', '游艇']
print("商品列表如下：")
print(li)
num_1 = input ('your num :')
print(li[int(num_1)])

'''