一、int类型与float类型
1、将纯数字类型转换成int
>>> res = int('1024') >>> print(res,type(res)) 1024 <class 'int'>
2、进制之间的转换
十进制转换成二进制
14 --> 1 1 1 0 >>> print(bin(14)) 0b1110 >>> >>> print(int('0b1110',2)) 14 >>>
十进制转八进制
14 --> 16 >>> print(oct(14)) 0o16 >>> >>> print(int('0o16',8)) 14 >>>
十进制转十六进制
14 --> e >>> print(hex(14)) 0xe >>> >>> print(int('0xe',16)) 14 >>>
进制运算主要用于数学运算和比较运算
二、字符串的内置方法
1、字符串可以把其他任意类型的数据都转换成字符串
>>> msg = 'hello' >>> print(msg,type(msg)) hello <class 'str'> >>> >>> obj = str({'egon':19}) >>> print(obj,type(obj)) {'egon': 19} <class 'str'> >>> >>> age = 19 >>> res = str(age) >>> print(res,type(res)) 19 <class 'str'> >>>
2、字符串的内置方法
- 取值(正向取,反向取,对于字符串只能进行读操作):
正向取值 >>> msg = 'hello world' >>> print(msg[0],msg[8]) h r 反向取值 >>> print(msg[-1],msg[-3]) d r >>>
扫描二维码关注公众号,回复: 9729361 查看本文章 - 切片(从一个大字符串中拷贝出一个小字符串)
正向取 msg = 'hello world' >>> res = msg[0:5:1] >>> print(res,'\n',msg) hello hello world >>> 反向取 >>> res = msg[5:0:-1] >>> print(res) olle >>> >>> res = msg[-1::-1] >>> print(res) dlrow olleh >>>
- 长度len
>>> print(len(msg)) 11 >>>
- 成员运算in 和 not in
>>> print('egon' in 'egon is very nb') True >>> >>> print('tank' not in 'egon is very nb') True >>>
- 移除字符串左右两侧的符号(默认为空格)
>>> name = ' egon ' >>> print(name.strip(),name) egon egon >>> >>> age_str = '****18***' >>> print(age_str.strip('*'),age_str) 18 ****18*** >>>
- 切分split(默认分割符为空格)
>>> str_obj = 'hellow egon, you are very nb' >>> print(str_obj.split(),'\n',str_obj) ['hellow', 'egon,', 'you', 'are', 'very', 'nb'] hellow egon, you are very nb >>> 指定字符分割 >>> userfile_path = '/opt/nubosh/vmsec/upload' >>> print(userfile_path.split('/'),'\n',userfile_path) ['', 'opt', 'nubosh', 'vmsec', 'upload'] /opt/nubosh/vmsec/upload >>>
- 需要掌握
1、strip、lstrip、rstrip >>> name = ' egon ' >>> print(name.strip()) egon >>> print(name.lstrip()) egon >>> print(name.rstrip()) egon 2、lower、upper >>> obj = 'egon' >>> print(obj.upper()) EGON >>> print(obj.lower()) egon >>> 3、startswith、endswith >>> file_path = '/opt/nubosh/vmsec/vmsec.db' >>> print(file_path.endswith('db')) True >>> print(file_path.startswith('/')) True >>> 4、split、rsplit(指定分割次数) ['/opt/nubosh/vmsec', 'vmsec.db'] >>> print(file_path.split('/',1)) ['', 'opt/nubosh/vmsec/vmsec.db'] >>> 5、format 6、join字符串拼接 file_path = '/opt/nubosh/vmsec/vmsec.db' >>> path_list = file_path.split('/')[0:-1:1] >>> print('/'.join(path_list+['log.txt'])) /opt/nubosh/vmsec/log.txt >>> 7、replace >>> import time >>> current_time = time.ctime(time.time()) >>> print(current_time) Tue Mar 10 16:57:26 2020 >>> res = current_time.replace(':','/') >>> print(res) Tue Mar 10 16/57/26 2020 >>> 8、判断字符串是否由纯数字组成 >>> print('123'.isdigit()) True >>> print('12.3'.isdigit()) False >>>
- 其他了解类型
# 4.3了解 #4.3.1、find,rfind,index,rindex,count msg='hello egon hahaha' # 找到返回起始索引 # print(msg.find('e')) # 返回要查找的字符串在大字符串中的起始索引 # print(msg.find('egon')) # print(msg.index('e')) # print(msg.index('egon')) # 找不到 # print(msg.find('xxx')) # 返回-1,代表找不到 # print(msg.index('xxx')) # 抛出异常 # msg='hello egon hahaha egon、 egon' # print(msg.count('egon')) #4.3.2、center,ljust,rjust,zfill # print('egon'.center(50,'*')) # print('egon'.ljust(50,'*')) # print('egon'.rjust(50,'*')) # print('egon'.zfill(10)) #4.3.3、expandtabs # msg='hello\tworld' # print(msg.expandtabs(2)) # 设置制表符代表的空格数为2 #4.3.4、captalize,swapcase,title # print("hello world egon".capitalize()) # print("Hello WorLd EGon".swapcase()) # print("hello world egon".title()) #4.3.5、is数字系列 #4.3.6、is其他 # print('abc'.islower()) # print('ABC'.isupper()) # print('Hello World'.istitle()) # print('123123aadsf'.isalnum()) # 字符串由字母或数字组成结果为True # print('ad'.isalpha()) # 字符串由由字母组成结果为True # print(' '.isspace()) # 字符串由空格组成结果为True # print('print'.isidentifier()) # print('age_of_egon'.isidentifier()) # print('1age_of_egon'.isidentifier()) num1=b'4' #bytes num2=u'4' #unicode,python3中无需加u就是unicode num3='四' #中文数字 num4='Ⅳ' #罗马数字 # isdigit只能识别:num1、num2 # print(num1.isdigit()) # True # print(num2.isdigit()) # True # print(num3.isdigit()) # False # print(num4.isdigit()) # False # isnumberic可以识别:num2、num3、num4 # print(num2.isnumeric()) # True # print(num3.isnumeric()) # True # print(num4.isnumeric()) # True # isdecimal只能识别:num2 print(num2.isdecimal()) # True print(num3.isdecimal()) # False print(num4.isdecimal()) # False