# str(li)
'''
li = [1, 2, 3]
s = str(li)
print(s,s[0])
'''
# 列表操作练习
'''
li = ['alex', 'wusir', 'eric', 'rain', 'alex']
l1 = len(li)
print(l1)
li.append('seven')
li.insert(0, 'Tony')
li[1] = 'Kelly'
li.extend([1, 'a', 3, 4, 'heart'])
li.extend('qwert')
li.pop(li.index('eric'))
l1 = li.pop(1)
del li[1:4]
li.reverse()
a = li.count('alex')
print(li, a)
li = [1, 3, 2, 'a', 4, 'b', 5, 'c']
l1 = li[0:3]
l2 = li[3:6]
l3 = li[0:-1:2]
l4 = li[1:6:2]
l5 = list(li[-1])
l6 = li[5:0:-2]
print(l1, l2, l3, l4, l5, l6)
li = [2, 3, 'k', ['qwe', 20, ['k1', ['tt', 3, '1']], 89], 'ab', 'adv']
li[3][2][1][0] = 'TT'
li[3][2][1][0] = li[3][2][1][0].upper()
li[1] = '100'
li.remove(3)
li.insert(1,'100')
print(li)
'''

# 字典 增
'''
dic1 = {'name': 'jin', 'sex': 'male', 'age': 18}
dic1['height'] = 185   # 没有键值对，增加
dic1['age'] = 16    #有键值对，覆盖
dic1.setdefault('weight', 150)
dic1.setdefault('name', 'dsds')  # 有键值对不动，没有才增加
'''

# 删
'''
dic1.pop('age', None)  # 有,返回值——值;无则返回None
dic1.popitem()  # 随机删除
del dic1['name']  # 无返回值
del dic1 # 删除字典
'''
# 改
'''
dic = {'name': 'jin', 'age': 18, 'sex': 'male'}
dic2 = {'name': 'alex', 'weight': 75}
dic2.update(dic)
'''
# 查
'''
dic1 = {'name': 'jin', 'sex': 'male', 'age': 18}
print(dic1.keys(), type(dic1.keys()))
print(dic1.values(), type(dic1.values()))
print(dic1.items(), type(dic1.items()))
# 2中循环打印
for i in dic1.items():
    for j in i:
        print(j)
for i, j in dic1.items():
    print(i,j)
print(dic1.get('name1',None))
'''