一、整形
1. base
#在16进制中的位置num = "b"v = int(num, base=16)print(v) #11
2. bit_length()
# 1 1# 2 10# 3 11# 4 100# 5 101# 当前数字的二进制，至少用n位表示age = 5r = age.bit_length()print(r) # 3age = 2r = age.bit_length()print(r) # 2
二、字符串
需要记住六个基本魔法：join(), split(), find(), strip(), upper(), lower()
1. find
test = "alexalex"v = test.find('lex',3)print(v)从第3个位置'x'查找'lex' 2. format
test = 'i am {name}, age {a}'print(test)v = test.format(name='alex',a=19)print(v)test = 'i am {0}, age {1}'print(test)v = test.format('alex',19)print(v)#格式化，传入的值 {"name": 'alex', "a": 19}test = 'i am {name}, age {a}'v1 = test.format(name='df',a=10)v2 = test.format_map({ "name": 'alex', "a": 19})print(v1)print(v2) test = "aLEx"#首字母大写v = test.capitalize()print(v)#所有字母大写v2 = test.upper()print(v2)# 所有变小写，casefold更牛逼，很多未知的对相应变小写v3 = test.casefold()print(v3)v4 = test.lower()print(v4)
4. center
#设置宽度，并将内容居中# 20 代指总长度# * 空白未知填充，一个字符，可有可无test = 'alex'v = test.center(20,"中")print(v) # 中中中中中中中中alex中中中中中中中中
5. count
# 去字符串中寻找，寻找子序列的出现次数test = "aLexalexr"v = test.count('ex')print(v) # 2test = "aLexalexr"v = test.count('ex',5,7)print(v) # 0v = test.count('ex',5,8)print(v) # 1 6. endswith(), startswith()
# 以什么什么结尾# 以什么什么开始test = "alex"v1 = test.endswith('ex')print(v1) # Falsev2 = test.startswith('ex')print(v2) # True 7. isalnum(), isalpha()
# 字符串中是否只包含 字母、数字或汉字test = "123d好"v1 = test.isalnum()print(v1) # True# 字符串中是否只包含 字母或汉字v2 = test.isalpha()print(v2) # False
8. isdecimal(), isdigit(), isnumeric()
# test = "二" # 1，② ， 是否为数字test = '12'v1 = test.isdecimal()v2 = test.isdigit() #包含②v3 = test.isnumeric() #包含“二”print(v1,v2,v3) #True True True
9. isprintable()
# 是否存在不可显示的字符# \t 制表符# \n 换行test = "oiuas\tdfkj"v = test.isprintable()print(v) # False
10. isspace()
# 15 判断是否全部是空格test = " "v = test.isspace()print(v) # True
11. istitle(), title()
# 16 判断是否是标题test = "Return True if all cased characters in S"v1 = test.istitle()print(v1) # Falsev2 = test.title()print(v2) # Return True If All Cased Characters In Sv3 = v2.istitle()print(v3) # True
12. join()
# 17 ***** 将字符串中的每一个元素按照指定分隔符进行拼接test = "你是风儿我是沙"print(test)t = ' 'v = t.join(test)print(v) # 你 是 风 儿 我 是 沙
13. islower(), isupper()
# 18 判断是否全部是大小写 和 转换为大小写test = "Alex"v1 = test.islower()v2 = test.lower()print(v1, v2) # False alexv1 = test.isupper()v2 = test.upper()print(v1,v2) # False ALEX
14. lstrip(), rstrip(), strip()
# 移除指定字符串test = "wxadx"v1 = test.lstrip('x')v2 = test.rstrip('x')v3 = test.strip('x')print(v1,v2,v3) # wxadx wxad wxad# 去除左右空白v = ' df 'print(v) # ' df 'v1 = v.lstrip()v2 = v.rstrip()v3 = v.strip()print(v1) # 'df 'print(v2) # ' df'print(v3) # 'df' 15. maketrans(), translate()
# 对应关系替换test = "aeiou"test1 = "12345"v = "asidufkasd;fiuadkf;adfkjalsdjf"m = str.maketrans("aeiou", "12345")new_v = v.translate(m)print(new_v) # 1s3d5fk1sd;f351dkf;1dfkj1lsdjf 16. partition(), rpartition()
# 21 分割为三部分test = "testasdsddfg"v = test.partition('s')print(v) # ('te', 's', 'tasdsddfg')v = test.rpartition('s')print(v) # ('testasd', 's', 'ddfg') 17. split(), rsplit()
# 分割为指定个数test = "testasdsddfg"v1 = test.split('s',2)print(v1) # ['te', 'ta', 'dsddfg']v2 = test.rsplit('s',2)print(v2) # ['testa', 'd', 'ddfg'] 18. splitlines()
# 分割，只能根据，true，false：是否保留换行test = "asdfadfasdf\nasdfasdf\nadfasdf"v1 = test.splitlines(True)print(v1) # ['asdfadfasdf\n', 'asdfasdf\n', 'adfasdf']v2 = test.splitlines(False)print(v2) # ['asdfadfasdf', 'asdfasdf', 'adfasdf']
19. swapcase()
# 大小写转换test = "aLex"v = test.swapcase()print(v) # AlEX
20. replace()
# 将指定字符串替换为指定字符串test = "alexalexalex"v = test.replace("ex",'bbb')print(v) #全部替换v = test.replace("ex",'bbb',2)print(v) #替换前两个
三、4个灰魔法：所有地方都能用
1. for循环
test = "郑建文妹子有种冲我来"for item in test: print(item)
郑
建文妹子有种冲我来2、索引
# 二、索引，下标，获取字符串中的某一个字符test = '123dg'v = test[3]print(v) # d
3、切片
# 三、切片test = '12df56'v = test[0:2]print(v) # 12d
4 、获取长度
# 四、获取长度# Python3： len获取当前字符串中由几个字符组成test = 'asdfg'v = len(test)print(v) # 5
四、一个深灰魔法
###################### 1个深灰魔法 ######################
# 字符串一旦创建，不可修改 # 一旦修改或者拼接，都会造成重新生成字符串# name = "zhengjianwen"
# age = "18" # # info = name + age # print(info)