python-07. various types of objects

Basic data types in detail one, str string

1.capitalize string first letter capitalization

　　Does not change itself, it generates a new value

1 name = ' Zhangsan ' 2 new_name = name.capitalize () 3 print (name) 4 print (new_name) 5 6 output: 7 zhangsan8 Zhangsan

2,casefold all uppercase to lowercase, Casefold can make any language uppercase lowercase

1 name = ' Sunchenguang ' 2 new_name = name.casefold () 3 print (name) 4 print (new_name) 5 6 output: 7 SunChenGuang8 Sunchenguang

3,Lower all uppercase to lowercase, lower can only change the English

1 name = ' Sunchenguang ' 2 new_name = name.lower () 3 print (name) 4 print (new_name) 5 6 output: 7 SunChenGuang8 Sunchenguang

4, Center Text Center

# parameter 1: indicates total length
# parameter 2: whitespace filled characters (length 1)

1 name = ' Sunchenguang ' 2 new_name = name.center (' # ') 3 print (name) 4 print (new_name) 5 6 output: 7 SunChenGuang8 # # # #SunChenG uang#####     

5.Count counts the number of occurrences of incoming values in a string

# parameter 1: the value to look for (sub-sequence)
# parameter 2: starting position (index)
# parameter 3: End position (index)

1 neme = ' Sunchenguang ' 2 v1 = Neme.count (' g ') 3 v2 = Neme.count (' g ', 0,6) 4 v3 = Neme.count (' g ', 3,9) 5 print (neme) 6 print (v1) 7 Print (v2) 8 print (v3) 9 10 output content: SunChenGuang12 313 114 2

6,EndsWith whether to end with xx, The return value is TRUE or False

1 name = ' Sunchegnuang ' 2 new_name = Name.endswith (' Ong ') 3 print (name) 4 print (new_name) 5 6 output content: 7 Sunchenguang8 True

7,StartsWith whether to start with xx, The return value is TRUE or False

1 name = ' Sunchenguang ' 2 new_name = Name.startswith (' gu ') 3 print (name) 4 print (new_name) 5 6 output content: 7 Sunchenguang8 True

8,expandtabs find the tab \ t, replace (contains the preceding Value)

# parameter is 8 by default

1 name = ' Sun\tchen\tguang\nsun\tchen\tlguang ' 2 new_name = name.expandtabs (ten) 3 print (name) 4 print (new_name) 5  6 output Content: 7 Sun    Chen    Guang 8 Sun Chen Guang 9 Sun       Chen      guang10 Sun Chen Guang

9. Find the index position of the specified sub-sequence

Find: There is a return index position, there is no return-1

Index: There is a return index position, there is no error

1 name = ' Sunchegnaung ' 2 v1 = name.find (' c ') 3 v2 = Name.index (' s ') 4 v3 = name.find (' x ') 5 # v4 = Name.index (' x ') 6 Print (v1, V2,v3) 7 8 Output content: 9 3 3-1

10. String Formatting

%: According to percent sign

1 v1 = ' name:%s; age:%s; gender:%s ' 2 new_v1 = v1% (' Sun Chenguang ', 20, ' male ') 3 print (new_v1) 4 5 output: 6 name: Sun Chenguang; age: 20; gender: Male

Format: according to Subscript

1 v2 = ' name: {0}; age: {1}; gender: {2} ' 2 new_v2 = V2.format (' Sun Chenguang ', 20, ' male ') 3 print (new_v2) 4 5 output: 6 name: Sun Chenguang; age: 20; gender: Male

Format_map: based on key value pairs

1 v3 = ' name: {name}; age: {gender} ' 2 new_v3 = v3.format_map ({' name ': ' Zhang San ', ' ages ': ' gender ': ' male '}) 3 print (new_v3) 4 5 Output content: 6 name: Zhang san; age: 20; gender: Male

11,isalnum judge whether it is a number, letter, Chinese characters

# numbers, letters, Kanji True

# Special Symbol False

1 name1 = ' utility bill ' 2 name2 = ' Utility bill ' 3 v1 = name1.isalnum () 4 v2 = name2.isalnum () 5 Print (v1,v2) 6 7 output content: 8 True False

12. Judging whether it is a number

isdecimal # ' 123 '

isdigit # ' 123 ', ' ② '

isnumeric # ' 123 ', ' two ', ' ② '

1 NUM1 = "123" 2 num2 = "②" 3 num3 = "two" 4 V1 = num1.isdecimal ()    # ' 123 ' 5 v2 = num2.isdigit ()      # ' 123 ', ' ② ' 6 v3 = Num3.isnumeric ()    # ' 123 ', ' two ', ' ② ' 7 print (v1,v2,v3) 8  9 Output Content: true True    

13,Isidentifier Determine whether the variable name is legitimate

1 name1 = ' guoshaolong1 ' 2 name2 = ' 1guoshaolong ' 3 v1 = name1.isidentifier () 4 v2 = name2.isidentifier () 5 Print (v1,v2) 6 7 output Content: 8 True False

14,islower judge whether all lowercase

1 name1 = ' Zhangsan ' 2 name2 = ' Zhangsan ' 3 v1 = name1.islower ()    #判断是否全部是小写4 v2 = name2.islower ()    #判断是否全部是小写5 Print ( V1,v2) 6 7 Output content: 8 True False

　　Isupper Determine if all are uppercase

1 Name3 = ' Zhangsan ' 2 name4 = ' Zhangsan ' 3 v3 = name3.isupper ()    #判断是否全部是大写4 v4 = name4.isupper ()    #判断是否全部是大写5 Print ( V3,v4) 6 7 Output content: 8 True False

15.Upper All caps

1 name = ' Sunchenguang ' 2 new_name = name.upper () 3 print (name) 4 print (new_name) 5 6 output: 7 Sunchenguang8 Zhangsan

Lower All lowercase

1 name = ' Zhangsan ' 2 new_name = name.lower () 3 print (name) 4 print (new_name) 5 6 output: 7 ZHANGSAN8 Zhangsan

16. does theisprintable contain the implied \ t

#不包含返回True, contains the return false

1 name1 = ' Zhangsan ' 2 name2 = ' Zhang\nsan ' 3 v1 = name1.isprintable () 4 v2 = name2.isprintable () 5 Print (v1,v2) 6 7 output: 8 Tru E False

17,isspace are all spaces

1 name = '  2 v = name.isspace () 3 Print (v) 4 5 output content: 6 True

18. element concatenation (element String) importance five Stars * * * *

1 name = ' Zhangsan ' 2 v1 = "_". Join (name) 3 Print (v1) 4  5 name_list = [' Zhang San ', ' John Doe ', ' Harry '] 6 v2 = "*". Join (name_list) 7 PR int (v2) 8  9 output content: z_h_a_n_g_s_a_n11 Zhang San * John Doe * Harry

19, left and right fill

　　 Center text centered (see 4th)

　　rjust Right padding

　　Ljust left padding

1 name = ' Zhangsan ' 2 v1 = name.rjust ("*")    #右填充3 v2 = name.ljust ("*")    #左填充4 print (v1) 5 print (v2) 6 7 output Content: 8 *********zhangsan9 zhangsan*********

20. Corresponding relationship + translation

1 m = Str.maketrans (' aeiou ', ' 12345 ') 2 name = ' ABCDEFGHIJKLMNOPQRSTUVWXYZ ' 3 v = name.translate (M) 4 print (v) 5 6 output content: 7 1BCD2 Fgh3jklmn4pqrst5vwxyz

21,partition segmentation, Preserving the elements of the Division

1 name = ' Zhang.san.si '
2 v = name.partition ('. ') 3 Print (v) 4 5 output content: 6 (' Zhang ', '. ', ' san.si ')

22. Replace replacement

1 name = ' zhang.san.si ' 2 v1 = name.replace ('. ', ' * ') 3 v2 = name.replace ('. ', ' * ', 1) 4 print (v1) 5 print (v2) 6 7 output: 8 zhang*s An*si9 zhang*san.si

23,strip removal of blank, \n,\t

1 name = '  zhangsan\t ' 2 v = name.strip () 3 print (name) 4 print (v) 5 6 output content: 7   Zhangsan   8 Zhangsan

24.swapcase Case Conversion

1 name = ' Zhangsan ' 2 v = name.swapcase () 3 print (name) 4 print (v) 5 6 output content: 7 ZhangSan8 Zhangsan

25,Zfill to the front padding 0

1 name = ' Zhangsan ' 2 v = name.zfill (3) Print (v) 4 5 output: 6 000000000zhangsan

26. Convertencode to bytes

1 name = ' Zhang San ' 2 v1 = Name.encode (encoding= ' utf-8 ') 3 v2 = Name.encode (encoding= ' GBK ') 4 print (v1) 5 print (v2) 6 7 output: 8 B ' \xe9 \x83\xad\xe5\xb0\x91\xe9\xbe\x99 ' 9 B ' \xb9\xf9\xc9\xd9\xc1\xfa '

two int integers

1,bit_length The binary representation of the current integer, the minimum number of digits

1 age1 = 1 2 age2 = 3 Age3 = 4 print (age1.bit_length ()) 5 print (age2.bit_length ()) 6 print (age3.bit_length ()) 7
   
    8 Output content: 9 110 411 7
   

2.to_bytes Gets the byte representation of the current data

1 Age = 202 V1 = age.to_bytes (10,byteorder= ' Big ') 3 v2 = age.to_bytes (10,byteorder= ' Little ') 4 print (v1) 5 print (v2) 6 7 output Content: 8 B ' \x00\x00\x00\x00\x00\x00\x00\x00\x00\x14 ' 9 B ' \x14\x00\x00\x00\x00\x00\x00\x00\x00\x00 '

third, BOOL Boolean value

1. Only true or False

1 v1 = 0 2 v2 = 1 3 v3 =-1 4 v4 = ' 5 v5 = [] 6 print (bool (v1)) 7 print (bool (v2)) 8 print (bool (v3)) 9 print (bool (v4)) 10 Print (bool (v5)) 11 12 output content: False14 True15 True16 False17 False

Iv. List of lists

1,Append Additional

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 user_list.append (' old five ') 3 print (user_list) 4 5 output content: 6 [' eldest ', ' Dick ', ' old three ', ' old four ', ' old five ']

2.Clear Clear

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 user_list.clear () 3 Print (user_list) 4 5 output content: 6 []

3. copy copy (light Copy)

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 v = user_list.copy () 3 print (user_list) 4 print (v) 5 6 output: 7 [' eldest brother ', ' Dick ', ' old three ', ' old four ']8 [' eldest ', ' Dick ', ' old three ', ' old four ']

4. Count counts

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ', ' old three ']2 v = user_list.count (' old three ') 3 print (user_list) 4 print (v) 5 6 output: 7 [' eldest ', ' Dick ', ' old Three ', ' Old four ', ' old three ']8 2

5,extend extension of the original list

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 user_list.extend ([' Guo Shaolong ', ' Little Dragon ']) 3 print (user_list) 4 5 output: 6 [' eldest ', ' Dick ', ' old three ', ' old four ', ' Guo Shaolong ', ' Little Dragon ']

6, Index to find the elements, no errors

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 v = user_list.index (' boss ') 3 Print (v) 4 5 output content: 6 0

7.Pop Delete and get element-delete according to index

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 v = user_list.pop (1) 3 print (v) 4 print (user_list) 5 6 output: 7 old 28 [' eldest brother ', ' old three ', ' old four ']

8, Remove delete-based on the value of the deletion

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 user_list.remove (' Dick ') 3 print (user_list) 4 5 output: 6 [' eldest ', ' old three ', ' old four ']

9,Reverse Flip

1 user_list = [' eldest ', ' Dick ', ' old three ', ' old four ']2 user_list.reverse () 3 Print (user_list) 4 5 output content: 6 [' old four ', ' old three ', ' Dick ', ' boss ']

10. Sort Order

1 positive order: 2 nums = [5,4,3,2,6,10,7] 3 nums.sort () 4 print (nums) 5  6 output: 7 [2, 3, 4, 5, 6, 7, ten] 8  9 10 Reverse: nums = [5,4,3,2,6,10,7]12 nums.sort (reverse=true) Print (nums) 14 15 output content: 16 [10, 7, 6, 5, 4, 3, 2]

11. Supplemental content:Range

1, Output 1-10

1 for I in range (1,11): 2     print (i) 3  4 output content: 5 1 6 2 7 3 8 4 9 510 611 712 813 914 10

2, output 1-10 Odd

1 for I in range (1,11,2): 2     print (i) 3 4 output content: 5 16 37 58 79 9

3, Reverse Output 10-1

1 for I in range (10,0,-1): 2     print (i) 3  4 output content: 5 10 6 9 7 8 8 7 9 610 511 412 313 214 1

4. Output List Contents + Serial number

1 name = [' Zhang San ', ' John Doe ', ' Harry ']2 for I in range (0,len (name)): 3     print (i+1,name[i]) 4 5 output: 6 1 Sheets 37 2 Li 48 3 Harry

12. Supplemental content:Enumerate generate an extra column of sequential numbers

1 name = [' Zhang San ', ' John Doe ', ' Harry ']2 for I,ele in enumerate (name,1): 3     print (i,ele) 4 5 output: 6 1 Sheets 37 2 Li 48 3 Harry

V. tuple: tuples (non-modifiable lists; immutable types)

# tuples If there is only one value, you need to add a comma at the end

1,Count Gets the number

1 user_tuple = (' Zhang San ', ' John Doe ', ' Harry ', ' Zhang San ',) 2 v = user_tuple.count (' Zhang San ') 3 Print (v) 4 5 output content: 6 2

2. Index Gets the first indexed position of a value

1 user_tuple = (' Zhang San ', ' John Doe ', ' Harry ', ' Zhang San ',) 2 v = user_tuple.index (' Zhang San ') 3 Print (v) 4 5 output content: 6 0

Vi. Dict: Dictionary

1.Clear Clear

1 dic = {' K1 ': ' v1 ', ' K2 ': ' v2 '}2 dic.clear () 3 Print (dic) 4 5 output content: 6 {}

2. Copy light copy

1 dic = {' K1 ': ' v1 ', ' K2 ': ' v2 '}2 v = dic.copy () 3 print (dic) 4 print (v) 5 6 output content: 7 {' K2 ': ' v2 ', ' k1 ': ' v1 '}8 ' K2 ': ' v2 ', ' K1 ': ' V1 '}

3, Get the specified value according to key; no error is present

1 dic = {' K1 ': ' v1 ', ' K2 ': ' v2 '}2 v1 = dic.get (' k111 ', ' 111 ') 3 Print (v1) 4 5 output content: 6 111

4,pop Delete and get the corresponding value values

1 dic = {' K1 ': ' v1 ', ' K2 ': ' v2 '}2 v1 = dic.pop (' K1 ') 3 Print (v1) 4 5 output content: 6 v1

5,popitem Random Delete key value pairs, and get to delete the key value

1 dic = {' K1 ': ' v1 ', ' K2 ': ' v2 '}2 v = dic.popitem () 3 print (v) 4 print (dic) 5 6 output content: 7 (' K2 ', ' v2 ') 8 {' K1 ': ' v1 '}

6,SetDefault increase, If there is no operation

1 dic = {' K1 ': ' v1 ', ' K2 ': ' v2 '}2 dic.setdefault (' K3 ', ' v3 ') 3 print (dic) 4 5 output content: 6 {' k1 ': ' v1 ', ' K2 ': ' v2 ', ' K3 ': ' v3 '}

7.Update Batch Add or modify

1 dic = {' K1 ': ' v1 ', ' K2 ': ' v2 '}2 dic.update ({' K3 ': ' v3 ', ' K1 ': ' v33333 '}) 3 print (dic) 4 5 output content: 6 {' K2 ': ' v2 ', ' K1 ': ' v33333 ', ' K ' 3 ': ' v3 '}

set, set (non-repeating list; mutable Type)

1, S1 exist, S2 does not exist

1 S1 = {"a", ' b ', ' C ', ' d ', ' e '} 2 s2 = {"a", ' b ', ' C ', ' d '} 3 v = s1.difference (s2) 4 print (v) 5 # # # # # # # # # s1, s2, Then Copy 6 s1.difference_update (s2) 7 Print (s1) 8  9 output content: {' e '}11 {' e '}

2, S2 exist, S1 does not exist

1 S1 = {"a", ' b ', ' d ', ' e '}2 s2 = {"a", ' b ', ' C ', ' d '}3 v = s2.difference (s1) 4 print (v) 5 6 output content: 7 {' c '}

python-07. various types of objects