字符串的拼接方法
（一）直接用“+”号，效率低（会在内存开辟另一块空间）
name = 'Jacky' + ' Zhao'
（二）字符串格式化
name = '%s %S' % ('Jacky','Zhao') （三）join方法
listname = ['Jacky',' Zhao']name = ''.join(listname)
（四）format格式化
name = 'jacky {0} {1} {2}'result = name.format('is','good','pepole')print(result)>>>jacky is good pepole name = '{name} is a good {what}'result = name.format(name='Jacky',what='pepole')print(result)>>>Jacky is a good pepole
int内部功能
#相加age = 18age.__add__(7) #等于18 + 7>>>25#divmod 取商和余数（两种方法）age.__divmod__(7) #等于 18 // 7 和18 % 7 组成的元组，就是18 / 7的商和余数(左除右)>>>（2，4）age.__rdivmod__(7) #等于 7 // 18 和7 % 18 组成的元组，就是7 / 18的商和余数（右除左）>>>（0，7）#返回绝对值age = -14age__abs__()>>>14
str内部功能
#包含name = 'jacky'result = name.__contains__('jac') #相当于 result = 'jac' in nameprint(result)>>>Trueresult = name.__contains__('jac6')print(result)>>>False
#首字母变大写name = 'jacky'result = name.capitalize()print(result)>>>Jacky#首字母变小写name = 'Jacky'result = name.casefold()print(result)>>>jacky#字母全部变大写name = 'jacky'result = name.swapcase()print(result)>>>JACKY#居中name = 'jacky'result = name.center(20,'*') #50表示一共50个字符位，*号表示除字符串外的位用*号代替print(result)>>>*******jacky********#找字符串中的了序列出现的次数file = 'alskjdhflakjsdhflasdfhlasdjfhl'a = file.count('d')print(a)>>>4b = file.count('d',5,15) #表示从第5个起到第10个字符中d 出现的次数print(b)>>>2#转码name = '小明'result = name.encode('gbk') #系统自动把字符串‘小明’的格式UTF8 转成unicode，再转成gbkprint(result)>>>b'\xd0\xa1\xc3\xf7'#判断是不是以某个字符结尾的name = 'jacky'result = name.endswith('ky')print(result)>>>True#把tab转移成空格，‘\t’表示tabname = 'j\tacky'result = name.expandtabs()print(result)>>>j acky#找字符串的的字符位置name = 'jacky zhao'result = name.find('k')result0 = name.index('k')result1 = name.find('L') #find方法中，如果找不到就返回‘-1’print(result,result0,result1)>>>3 3 -1result2 = name.index('L') #index方法中，如果找到就返回‘报错：not found’>>>result2 = name.index('L')ValueError: substring not found#字符转换name = 'kbkbkbkbkbk'result = name.replace('k','b') #把‘k’全部转换成‘b’print(result)>>>bbbbbbbbbbbname = 'kbkbkbkbkbk'result = name.replace('k','b',4) #把前4个‘k’转换成‘b’print(result)>>>bbbbbbbbkbk
元组内部功能
#元组get取值dic = {'k1':'v1','k2':'v2'}print(dic.get('k1'))>>>v1print(dic.get('k2'))>>>v2print(dic.get('k3')) #如果key不存在，显示none（默认值）>>>Noneprint(dic.get('k3','jacky')) #如果key不存，传入的参数才能生效>>>jackyprint(dic.keys()) #获取所有的key值>>>dict_keys(['k1', 'k2'])print(dic.values()) #获取所有的key的值>>>dict_values(['v1', 'v2'])print(dic.items()) #获取所有的键值对>>>dict_items([('k1', 'v1'), ('k2', 'v2')])dic.pop('k1') #删除指定的键值对print(dic)>>>{'k2': 'v2'}