失眠网 > python三种基本数据类型_python基础数据类型

python三种基本数据类型_python基础数据类型

时间：2021-07-29 18:44:03

python常用的数据类型包括整型(int)、字符串(str)、布尔值(bool)、列表(list)、元组(tuple)、字典(dict)、集合(set)

整型(int)

int操作方法

bit_length()就是查看十进制数转换成二进制在内存中占用了多少长度

1 a = 5

2 print(a.bit_length()) #当十进制用二进制表示时，最少使用的位数 3

int、bool、str三种转换

>>> i = 10 # int --> str

>>>str(i)10

>>> ii = -1

>>>str(ii)-1

>>> iii =0>>>str(iii)

>>> iiii = 000

>>>str(iiii)

1 >>> s1 = 20 # str --> int

2 >>>int(s1)3 20

4 >>> s2 = 500

5 >>>int(s2)6 500

7 >>> s3 = -122

8 >>>int(s3)9 -122

10 >>>

1 >>> i = 5 # int --> bool

2 >>>bool(i)3 True4 >>> a = -1

5 >>>bool(a)6 True7 >>> b =08 >>>bool(b)9 False

>>> int(True) #bool --> int

>>>int(False)

0>>>

>>> s4 = hello #str --> bool

>>>bool(s4)

True>>> s5 =

>>>bool(s5)

True>>> s6 = \

>>>bool(s6)

False

1 >>>str(True) # bool --> str2 True

3 >>>str(False)4 False

字符串(str)

python中凡是使用引号引起来的数据可以称为字符串类型，组成字符串的每个元素称为字符。

组成字符串的字符元素从左到右依次排列，是有顺序的(从0开始)。对字符串进行索引，切片出来的数据都是字符串类型。

切片操作

1 >>> s = python学习课程

2 >>> s1 =s[0]3 >>>s14 p

5 >>>type(s1)6

7 >>> s2 = s[6]8 >>>s29 学

10 >>> s3 = s[-1]11 >>>s312 程

13 >>> s4 = s[0:6]14 >>>s415 python

16 >>> s5 = s[:6]17 >>>s518 python

19 >>> s6 = s[6:]20 >>>s621 学习课程

22 >>> s7 = s[:8:2] #2 代表步长

23 >>>s724 pto学

25 >>> s8 = s[-1:-8]26 >>>s827 \

28 >>> s8 = s[-1:-8:-1]29 >>>s830 程课习学noh

31 >>> s9 =s[:]32 >>>s933 python学习课程

34 >>> s10 = s[-1:]35 >>>s1036 程

View Code

1 s = "123a4b5c"

2 s1 = s[:3]3 print(s1) #"123"

4 s2 = s[3:6]5 print(s2) #"a4b"

6 s3 = s[::2]7 print(s3) #"1345"

8 s4 = s[1:-2:2]9 print(s4) #"2ab"

10 s5 = s[-1]11 print(s5) #"c"

12 s6 = s[-3::-2]13 print(s6) #"ba2"

View Code

1 >>> s = "Turn right on this street."

2 >>> s1 = s.upper() #变大写

3 >>>s14 TURN RIGHT ON THIS STREET.

5 >>> s2 = s.lower() #变小写

6 >>>s27 urn right on this street.

8 >>> s.count("r")9 3

10 >>>

11 >>> s.count("r", 0, 9)12 2

13 >>> ss = "ascaljcdashc;LS"

14 >>>ss15 ascaljcdashc;LS

16 >>> ss.startswith("as") #以...开头

17 True18 >>> ss.startswith("asd")19 False20 >>> ss.startswith("sw", 5, -1) #加了切片

21 False22 >>> ss.startswith("jc", 5 , -1)23 True24 >>> ss.endswith("S") #判断是否以...结尾

25 True26 >>> ss.endswith("c", 6, 11)27 False28 >>> ss.endswith("c", 6, 12)29 True30 >>> s = "Hope has always been like a teenager, clean and pure peace of mind"

31 >>>s.split()32 [Hope, has, always, een, like, a, eenager,, clean, and, pure, peace, of, mind]33

34 >>> s.split(",")35 [Hope has always been like a teenager, clean and pure peace of mind]36

37 >>> s1 = "name:alex:age:18:gender:male"

38 >>> s1.split(":")39 [ ame, alex, age, 18, gender, male]40 >>> s1.split(":",2)41 [ ame, alex, age:18:gender:male]42 >>> s2 = ":tom:ethan:alex"

43 >>> s2.split(":")44 [ , om, ethan, alex]45 >>> s3 = "alex"

46 >>> "+".join(s3)47 a+l+e+x

48 >>> type("+".join(s3))49

50 >>> s4 = "name"

51 >>> " ".join(s3, s4)52 Traceback (most recent call last):53 File "", line 1, in

54 TypeError: join() takes exactly one argument (2given)55 >>> ss =s.split()56 >>>ss57 [Hope, has, always, een, like, a, eenager,, clean, and, pure, peace, of, mind]58 >>> " ".join(ss)59 Hope has always been like a teenager, clean and pure peace of mind

61 >>> li = ["s", "a", "b", "f", 33]62 >>>type(li)63

64 >>> "".join(li)65 Traceback (most recent call last):66 File "", line 1, in

67 TypeError: sequence item 4: expected str instance, int found68 >>> s = "Hope has always been like a teenager, clean and pure peace of mind"

69 >>>s.split()70 [Hope, has, always, een, like, a, eenager,, clean, and, pure, peace, of, mind]71 >>>

72 >>> s.split(",")73 [Hope has always been like a teenager, clean and pure peace of mind]74

75 >>> s1 = "name:alex:age:18:gender:male"

76 >>> s1.split(":")77 [ ame, alex, age, 18, gender, male]78 >>> s1.split(":",2)79 [ ame, alex, age:18:gender:male]80 >>> s2 = ":tom:ethan:alex"

81 >>> s2.split(":")82 [ , om, ethan, alex]83

84 >>> s3 = "alex"

85 >>> "+".join(s3)86 a+l+e+x

87 >>> type("+".join(s3))88

89 >>> s4 = "name"

90 >>> " ".join(s3, s4)91 Traceback (most recent call last):92 File "", line 1, in

93 TypeError: join() takes exactly one argument (2given)94 >>> ss =s.split()95 >>>ss96 [Hope, has, always, een, like, a, eenager,, clean, and, pure, peace, of, mind]97 >>> " ".join(ss)98 Hope has always been like a teenager, clean and pure peace of mind

100 >>> li = ["s", "a", "b", "f", 33]101 >>>type(li)102

103 >>> "".join(li)104 Traceback (most recent call last):105 File "", line 1, in

106 TypeError: sequence item 4: expected str instance, int found107 >>> s= "hello"

108 >>> s.strip() #去除空格

109 hello

110 >>> s5 = "as你好jhd"

111 >>> s5.strip("ajhsd")112 你好

113 >>> s5.strip("ajhs")114 你好jhd

115 >>> s6 = "as你r好jhd"

116 >>> s6.strip("ajhsd")117 你r好

118 >>>

119 >>> "**barry*****".strip()120 **barry*****