07 Python common data structures

Common data structures in Python can be collectively referred to as containers. There are three main types of containers: sequence (list, tuple and string), mapping (such as dictionary) and set.

1. Sequence

The sequence is ordered, and each element in the sequence has its own number. Python has 6 built-in sequences, including lists, tuples, strings, Unicode strings, buffer objects, and xrange objects.

1.1 string

1.1.1 create string

a = 'hello world'
print(type(a)) # <class 'str'>

name1 = 'Tom'
# The three quotation mark string supports line feed
b = ''' i am Tom, 
        nice to meet you! '''
c = "I'm Tom"
d = 'I\'m Tom'

1.1.2 string input and output

# output
print('hello world')
name = 'Tom'
print('My name is%s' % name)
print(f'My name is{name}')
# input
name = input('Please enter your name:')
print(f'The name you entered is{name}')
print(type(name))

1.1.3 subscript

Subscript, also known as index, is the number, starting from 0.

name = "abcdef"

print(name[1])
print(name[0])
print(name[2])

1.1.4 slicing

Slicing refers to the operation of intercepting part of the operated object. String, list and tuple all support slicing operation.

sequence[Start position subscript:End position subscript:step]

be careful

Excluding the data corresponding to the end position subscript, positive and negative integers can be used;
The step size is the selection interval, which can be positive or negative integers. The default step size is 1.

name = "abcdefg"

print(name[2:5:1])  # cde
print(name[2:5])  # cde
print(name[:5])  # abcde
print(name[1:])  # bcdefg
print(name[:])  # abcdefg
print(name[::2])  # aceg
print(name[:-1])  # abcdef, negative 1 indicates the penultimate data
print(name[-4:-1])  # def
print(name[::-1])  # gfedcba

1.1.5 common operation methods

1.1.5.1 search

The so-called string search method is to find the position or number of occurrences of the substring in the string.

find()
Check whether a substring is included in the string. If the subscript is at the beginning of the substring, otherwise - 1 will be returned.

String sequence.find(Substring, Start position subscript, End position subscript)

Note: the start and end subscripts can be omitted, indicating that they are found in the whole string sequence.

mystr = "hello world and itcast and itheima and Python"

print(mystr.find('and'))  # 12
print(mystr.find('and', 15, 30))  # 23
print(mystr.find('ands'))  # -1

index()
Detect whether a substring is included in this string. If the subscript is returned at the beginning of this substring, otherwise an exception will be reported.

String sequence.index(Substring, Start position subscript, End position subscript)

Note: the start and end subscripts can be omitted, indicating that they are found in the whole string sequence.

mystr = "hello world and itcast and itheima and Python"

print(mystr.index('and'))  # 12
print(mystr.index('and', 15, 30))  # 23
print(mystr.index('ands'))  # report errors

rfind()
It has the same function as find(), but the search direction starts from the right.
rindex()
It has the same function as index(), but the search direction starts from the right.
count()
Returns the number of occurrences of a substring in a string

String sequence.count(Substring, Start position subscript, End position subscript)

Note: the start and end subscripts can be omitted, indicating that they are found in the whole string sequence.

mystr = "hello world and itcast and itheima and Python"

print(mystr.count('and'))  # 3
print(mystr.count('ands'))  # 0
print(mystr.count('and', 0, 20))  # 1

1.1.5.2 modification

Modifying a string means modifying the data in the string in the form of a function.

replace(): replace

String sequence.replace(Old substring, New substring, Replacement times)

Note: if the replacement times exceed the occurrence times of the substring, the replacement times are the occurrence times of the substring.

mystr = "hello world and itcast and itheima and Python"

# Result: hello world he itcast he itheima he Python
print(mystr.replace('and', 'he'))
# Result: hello world he itcast he itheima he Python
print(mystr.replace('and', 'he', 10))
# Result: hello world and itcast and itheima and Python
print(mystr)

Note: data can be divided into variable type and immutable type according to whether it can be modified directly. When modifying the data of string type, the original string cannot be changed. It belongs to the type that cannot modify the data directly, that is, the immutable type.

split()
Splits the string according to the specified character.

String sequence.split(Split character, num)

Note: num indicates the number of split characters. The number of data to be returned is num+1.

mystr = "hello world and itcast and itheima and Python"

# Result: ['hello world', 'itcast', 'itheima', 'Python']
print(mystr.split('and'))
# Result: ['hello world', 'itcast', 'itheima and Python']
print(mystr.split('and', 2))
# Results: ['hello', 'world', 'and', 'itcast', 'and', 'itheima', 'and', 'Python']
print(mystr.split(' '))
# Results: ['Hello ',' world ',' itcast and itheima and Python ']
print(mystr.split(' ', 2))

join()
Combining strings with one character or substring is to combine multiple strings into a new string.

Character or substring.join(A sequence of multiple strings)

list1 = ['chuan', 'zhi', 'bo', 'ke']
t1 = ('aa', 'b', 'cc', 'ddd')
# Result: chuan_zhi_bo_ke
print('_'.join(list1))
# Result: AA b... cc... ddd
print('...'.join(t1))

capitalize()
Converts the first character of a string to uppercase.

mystr = "hello world and itcast and itheima and Python"

# Result: Hello world and itcast and itheima and python
print(mystr.capitalize())

Note: after the capitalization() function is converted, only the first character of the string is capitalized, and all other characters are lowercase.

title()
Converts the first letter of each word in a string to uppercase.

mystr = "hello world and itcast and itheima and Python"

# Result: Hello World And Itcast And Itheima And Python
print(mystr.title())

lower()
Converts uppercase to lowercase in a string.

mystr = "hello world and itcast and itheima and Python"

# Result: hello world and itcast and itheima and python
print(mystr.lower())

upper()
Converts the small case of a string to uppercase.

mystr = "hello world and itcast and itheima and Python"

# Result: HELLO WORLD AND ITCAST AND ITHEIMA AND PYTHON
print(mystr.upper())

lstrip()
Delete the white space character to the left of the string.

mystr = " hello world and itcast and itheima and Python "

# hello world and itcast and itheima and Python 
print(mystr.lstrip())
#  hello world and itcast and itheima and Python
print(mystr.rstrip())
# hello world and itcast and itheima and Python
print(mystr.strip())

rstrip() removes the white space character to the right of the string.
strip() deletes white space characters on both sides of the string

ljust()
Returns a left justified original string and fills it with a new string of the corresponding length using the specified character (default space).

String sequence.ljust(length, Fill character)

mystr2='hello'
mystr2.ljust(10,'.') # 'hello.....'
mystr2.ljust(10) # 'hello     '
mystr2.rjust(10,'.') # '.....hello'
mystr2.center(10,'.') # '..hello...'

rjust() returns a right aligned original string and fills it with a new string of corresponding length with the specified character (default space). The syntax is the same as ljust().
center() returns a new string centered on the original string and filled with the specified character (default space) to the corresponding length. The syntax is the same as ljust().

1.1.5.3 judgment

The so-called judgment is to judge whether it is True or False. The returned result is Boolean data type: True or False.

startswith()

Check whether the string starts with the specified substring. If yes, it returns True; otherwise, it returns False. If the start and end position subscripts are set, check within the specified range.

String sequence.startswith(Substring, Start position subscript, End position subscript)

mystr = "hello world and itcast and itheima and Python   "

# Result: True
print(mystr.startswith('hello'))

# Result False
print(mystr.startswith('hello', 5, 20))

endswith()
Check whether the string ends with the specified substring. If yes, it returns True; otherwise, it returns False. If the start and end position subscripts are set, check within the specified range.

String sequence.endswith(Substring, Start position subscript, End position subscript)

mystr = "hello world and itcast and itheima and Python"

# Result: True
print(mystr.endswith('Python'))

# Result: False
print(mystr.endswith('python'))

# Result: False
print(mystr.endswith('Python', 2, 20))

isalpha()
Returns True if the string has at least one character and all characters are letters, otherwise returns False.

mystr1 = 'hello'
mystr2 = 'hello12345'

# Result: True
print(mystr1.isalpha())

# Result: False
print(mystr2.isalpha())

isdigit()
Returns True if the string contains only numbers; otherwise, returns False.

mystr1 = 'aaa12345'
mystr2 = '12345'

# Result: False
print(mystr1.isdigit())

# Result: False
print(mystr2.isdigit())

isalnum()
Returns True if the string has at least one character and all characters are letters or numbers, otherwise returns False.

mystr1 = 'aaa12345'
mystr2 = '12345-'

# Result: True
print(mystr1.isalnum())

# Result: False
print(mystr2.isalnum())

isspace()
Returns True if the string contains only white space; otherwise, returns False.

mystr1 = '1 2 3 4 5'
mystr2 = '     '

# Result: False
print(mystr1.isspace())

# Result: True
print(mystr2.isspace())

1.2 tuples

Tuple characteristics:

Use parentheses () and separate the data with commas;
Data can be different data types;
A tuple can store multiple data, and the data in the tuple cannot be modified (immutable type)

1.2.1 creating tuples

# Multiple data tuples
t1 = (10, 20, 30)

# Single data tuple
t2 = (10,)

Note: if the defined tuple has only one data, add a comma after the data, otherwise the data type is the only data type of the data

t2 = (10,)
print(type(t2))  # tuple

t3 = (20)
print(type(t3))  # int

t4 = ('hello')
print(type(t4))  # str

1.2.2 common operations

Tuple data does not support modification, only search.

Find data by subscript

tuple1 = ('aa', 'bb', 'cc', 'bb')
print(tuple1[0])  # aa

index()
Find a data. If the data exists, return the corresponding subscript. Otherwise, an error is reported. The syntax is the same as the index method of list and string.

tuple1 = ('aa', 'bb', 'cc', 'bb')
print(tuple1.index('aa'))  # 0

count()
Count the number of times a data appears in the current tuple.

tuple1 = ('aa', 'bb', 'cc', 'bb')
print(tuple1.count('bb'))  # 2

len()
Count the number of data in tuples.

tuple1 = ('aa', 'bb', 'cc', 'bb')
print(len(tuple1))  # 4

Modify variable type elements in tuples

If the direct data in the tuple is modified, an error will be reported immediately. However, if there is a list in the tuple, modifying the data in the list is supported, so self-awareness is very important.

tuple1 = ('aa', 'bb', 'cc', 'bb')
tuple1[0] = 'aaa' # report errors

tuple2 = (10, 20, ['aa', 'bb', 'cc'], 50, 30)
print(tuple2[2])  # Access to list

# Results: (10, 20, ['aaaaa ',' BB ',' CC '], 50, 30)
tuple2[2][0] = 'aaaaa'
print(tuple2)

1.3 list

1.3.1 create list

# [data 1, data 2, data 3, data 4...] 

lst1=[1,2,3]
lst2=list() # []

1.3.2 common operations of list

Add, delete, modify and check.

1.3.2.1 search

subscript

name_list = ['Tom', 'Lily', 'Rose']

print(name_list[0])  # Tom
print(name_list[1])  # Lily
print(name_list[2])  # Rose

function

index()

List sequence.index(data, Start position subscript, End position subscript)

name_list = ['Tom', 'Lily', 'Rose']

print(name_list.index('Lily', 0, 2))  # 1

count()
Counts the number of times the specified data appears in the current list.

name_list = ['Tom', 'Lily', 'Rose']

print(name_list.count('Lily'))  # 1

len()
Access list length, that is, the number of data in the list.

name_list = ['Tom', 'Lily', 'Rose']

print(len(name_list))  # 3

Judge whether it exists

In: judge whether the specified data is in a list sequence. If yes, return True; otherwise, return False
Not in: judge whether the specified data is not in a list sequence. If not, return True; otherwise, return False

name_list = ['Tom', 'Lily', 'Rose']

# Result: True
print('Lily' in name_list)

# Result: False
print('Lilys' in name_list)

# Result: False
print('Lily' not in name_list)

# Result: True
print('Lilys' not in name_list)

1.3.2.2 add

append()
Append data to the end of the list.

List sequence.append(data)

When adding data to the list, the specified data is directly added to the original list, that is, the original list is modified, so the list is variable type data.

name_list = ['Tom', 'Lily', 'Rose']

name_list.append('xiaoming')

# Results: ['Tom', 'Lily', 'Rose', 'xiaoming']
print(name_list)

If the data appended by append() is a sequence, the whole sequence is appended to the list

extend()
Add data at the end of the list. If the data is a sequence, add the data of this sequence to the list one by one.

List sequence.extend(data)

name_list = ['Tom', 'Lily', 'Rose']
name_list.extend('xiaoming')
# Results: ['Tom', 'Lily', 'Rose', 'x', 'I', 'a', 'o','m ',' I ',' n ',' g ']
print(name_list)

name_list = ['Tom', 'Lily', 'Rose']
name_list.extend(['xiaoming', 'xiaohong'])
# Results: ['Tom', 'Lily', 'Rose', 'xiaoming', 'xiaohong']
print(name_list)

insert()
Add data at the specified location.

List sequence.insert(Position subscript, data)

name_list = ['Tom', 'Lily', 'Rose']

name_list.insert(1, 'xiaoming')

# Results: ['Tom', 'xiaoming', 'Lily', 'Rose']
print(name_list)

1.3.2.3 delete

del()

del target

Delete list

name_list = ['Tom', 'Lily', 'Rose']

Delete specified data

name_list = ['Tom', 'Lily', 'Rose']

del name_list[0]

# Result: ['lily ',' Rose ']
print(name_list)

pop()
Delete the data of the specified subscript (the last one by default) and return the data.

List sequence.pop(subscript)

name_list = ['Tom', 'Lily', 'Rose']

del_name = name_list.pop(1)

# Result: Lily
print(del_name)

# Result: [Tom ',' Rose ']
print(name_list)

remove()
Remove the first match of a data in the list.

List sequence.remove(data)

name_list = ['Tom', 'Lily', 'Rose']

name_list.remove('Rose')

# Result: [Tom ',' Lily ']
print(name_list)

clear()
clear list

name_list = ['Tom', 'Lily', 'Rose']

name_list.clear()
print(name_list) # Result: []

1.3.2.4 modification

Modify specified subscript data

name_list = ['Tom', 'Lily', 'Rose']

name_list[0] = 'aaa'

# Result: ['aaa ',' Lily ',' Rose ']
print(name_list)

reverse(): reverse

num_list = [1, 5, 2, 3, 6, 8]

num_list.reverse()

# Result: [8, 6, 3, 2, 5, 1]
print(num_list)

sort() sort

Sequence list.sort( key=None, reverse=False)

num_list = [1, 5, 2, 3, 6, 8]

num_list.sort()

# Results: [1, 2, 3, 5, 6, 8]
print(num_list)

1.3.2.5 copying

copy()

name_list = ['Tom', 'Lily', 'Rose']

name_li2 = name_list.copy()

# Result: ['Tom', 'Lily', 'Rose']
print(name_li2)

1.3.3 list loop traversal

# while
name_list = ['Tom', 'Lily', 'Rose']

i = 0
while i < len(name_list):
    print(name_list[i])
    i += 1

# for
name_list = ['Tom', 'Lily', 'Rose']

for i in name_list:
    print(i)

1.3.4 list nesting

name_list = [['Xiao Ming', 'Xiao Hong', 'Little green'], ['Tom', 'Lily', 'Rose'], ['Zhang San', 'Li Si', 'Wang Wu']]

# Step 1: click the subscript to find the list where Li Si is located
print(name_list[2])

# Step 2: from the list where Li Si is located, click the subscript to find the data Li Si
print(name_list[2][1])

2. Mapping

2.1 dictionary

Dictionaries

2.1.1 create dictionary

Dictionary features:

The symbol is braces
The data appears in the form of key value pairs
Key value pairs are separated by commas

# There is a data dictionary
dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}

# Empty dictionary
dict2 = {}

dict3 = dict()

Take the element in seq sequence as the key of the dictionary, and value is the initial value corresponding to all keys of the dictionary

dict.fromkeys(seq[, value])

seq – dictionary key value list.
Value – optional parameter to set the value of key sequence (seq).

seq = ('Google', 'Runoob', 'Taobao')
 
thisdict = dict.fromkeys(seq)
print "The new dictionary is : %s" %  str(dict)
# The new dictionary is: {Google ': none,' Taobao ': none,' runoob ': none}
thisdict = dict.fromkeys(seq, 10)
print "The new dictionary is : %s" %  str(thisdict)
# The new dictionary is: {Google ': 10,' Taobao ': 10,' runoob ': 10}

2.1.2 common operations of dictionary

Add, delete, modify and query

2.1.2.1 add

Dictionary sequence[key] = value

Note: if the key exists, modify the value corresponding to the key; If the key does not exist, add this key value pair.

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}

dict1['name'] = 'Rose'
# Results: {name ':' Rose ',' age ': 20,' gender ':' male '}
print(dict1)

dict1['id'] = 110

# {'name': 'Rose', 'age': 20, 'gender': 'male', 'id': 110}
print(dict1)

2.1.2.2 delete

del() /del
Delete the dictionary or delete the specified key value pair in the dictionary

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}

del dict1['gender']
# Result: {name ':'Tom','age ': 20}
print(dict1)

clear
Empty dictionary

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}

dict1.clear()
print(dict1)  # {}

2.1.2.3 modification

Modify according to key

Dictionary sequence[key] = value

Note: if the key exists, modify the value corresponding to the key; If the key does not exist, add this key value pair.

update()
Update the key / value pair of dictionary dict2 into dict.

dict.update(dict2)

tinydict = {'Name': 'Zara', 'Age': 7}
tinydict2 = {'Sex': 'female' }

tinydict.update(tinydict2)
print ("Value : %s" %  tinydict)
# Value : {'Age': 7, 'Name': 'Zara', 'Sex': 'female'}

2.1.2.4 check

key value search

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}
print(dict1['name'])  # Tom
print(dict1['id'])  # report errors

If the key currently searched exists, the corresponding value will be returned; Otherwise, an error will be reported.

get()

Dictionary sequence.get(key, Default value)

Note: if the key currently searched does not exist, the second parameter (default value) is returned. If the second parameter is omitted, None is returned.

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}
print(dict1.get('name'))  # Tom
print(dict1.get('id', 110))  # 110
print(dict1.get('id'))  # None

keys()

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}
print(dict1.keys())  # dict_keys(['name', 'age', 'gender'])

values()

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}
print(dict1.values())  # dict_values(['Tom', 20, 'male'])

items()

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}
print(dict1.items())  # dict_ Items ([('name ',' Tom '), ('age', 20), ('gender ',' male '))

2.1.3 dictionary loop traversal

dict1 = {'name': 'Tom', 'age': 20, 'gender': 'male'}
# Traversal key
for key in dict1.keys():
    print(key)
# Traversal value
for value in dict1.values():
    print(value)
# Traversal element
for item in dict1.items():
    print(item)
# Traverse key value pairs
for key, value in dict1.items():
    print(f'{key} = {value}')

3. Set

Collection features:

Set can remove duplicate data;
The set data is out of order, so subscripts are not supported

3.1 creating collections

Create a collection using {} or set(), but if you want to create an empty collection, you can only use set(), because {} is used to create an empty dictionary.

s1 = {10, 20, 30, 40, 50}
print(s1)

s2 = {10, 30, 20, 10, 30, 40, 30, 50}
print(s2)

s3 = set('abcdefg')
print(s3)

s4 = set()
print(type(s4))  # set

s5 = {}
print(type(s5))  # dict

3.2 common operation methods of collection

3.2.1 add

add()

s1 = {10, 20}
s1.add(100)
s1.add(10)
print(s1)  # {100, 10, 20}

Because the set has the function of de duplication, when the data added to the set is the existing data of the current set, no operation will be carried out.

update()

The additional data is a sequence.

s1 = {10, 20}
# s1.update(100)  # report errors
s1.update([100, 200])
s1.update('abc')
print(s1)

3.2.2 delete

remove()
Delete the specified data in the collection. If the data does not exist, an error will be reported

s1 = {10, 20}

s1.remove(10)
print(s1)

s1.remove(10)  # report errors
print(s1)

discard()
Delete the specified data in the collection. If the data does not exist, no error will be reported.

s1 = {10, 20}

s1.discard(10)
print(s1)

s1.discard(10)
print(s1)

pop()
Randomly delete a data in the set and return this data.

s1 = {10, 20, 30, 40, 50}

del_num = s1.pop()
print(del_num)
print(s1)

3.2.1 check

In determines whether the data is in the set sequence
not in judge whether the data is in the set sequence

s1 = {10, 20, 30, 40, 50}

print(10 in s1) # True
print(10 not in s1) # False

4. Public operation

4.1 operators

operator	describe	Supported container types
+	merge	String, list, tuple
*	copy	String, list, tuple
in	Does the element exist	String, list, tuple, dictionary
not in	Does the element not exist	String, list, tuple, dictionary

# +
# 1. String 
str1 = 'aa'
str2 = 'bb'
str3 = str1 + str2
print(str3)  # aabb
# 2. List 
list1 = [1, 2]
list2 = [10, 20]
list3 = list1 + list2
print(list3)  # [1, 2, 10, 20]
# 3. Tuple 
t1 = (1, 2)
t2 = (10, 20)
t3 = t1 + t2
print(t3)  # (10, 20, 100, 200)

# *
# 1. String
print('-' * 10)  # ----------
# 2. List
list1 = ['hello']
print(list1 * 4)  # ['hello', 'hello', 'hello', 'hello']
# 3. Tuple
t1 = ('world',)
print(t1 * 4)  # ('world', 'world', 'world', 'world')

# in or not in 
# 1. String
print('a' in 'abcd')  # True
print('a' not in 'abcd')  # False
# 2. List
list1 = ['a', 'b', 'c', 'd']
print('a' in list1)  # True
print('a' not in list1)  # False
# 3. Tuple
t1 = ('a', 'b', 'c', 'd')
print('aa' in t1)  # False
print('aa' not in t1)  # True

4.2 public methods

function	describe
len()	Calculate the number of elements in the container
Del or del()	delete
max()	Returns the maximum value of the element in the container
min()	Returns the minimum value of the element in the container
range(start, end, step)	Generate a number from start to end in step for the for loop
enumerate()	Function is used to combine a traversable data object (such as list, tuple or string) into an index sequence, and list data and data subscripts at the same time. It is generally used in the for loop.

len()

# 1. String
str1 = 'abcdefg'
print(len(str1))  # 7

# 2. List
list1 = [10, 20, 30, 40]
print(len(list1))  # 4

# 3. Tuple
t1 = (10, 20, 30, 40, 50)
print(len(t1))  # 5

# 4. Assemble
s1 = {10, 20, 30}
print(len(s1))  # 3

# 5. Dictionary
dict1 = {'name': 'Rose', 'age': 18}
print(len(dict1))  # 2

del()

# 1. String
str1 = 'abcdefg'
del str1
print(str1)

# 2. List
list1 = [10, 20, 30, 40]
del(list1[0])
print(list1)  # [20, 30, 40]

max() min()

# 1. String
str1 = 'abcdefg'
print(min(str1))  # a
print(max(str1))  # g

# 2. List
list1 = [10, 20, 30, 40]
print(min(list1))  # 10
print(max(list1))  # 40

range()

# 1 2 3 4 5 6 7 8 9
for i in range(1, 10, 1):
    print(i)

# 1 3 5 7 9
for i in range(1, 10, 2):
    print(i)

# 0 1 2 3 4 5 6 7 8 9
for i in range(10):
    print(i)

Note: the sequence generated by range() does not contain the end number.

enumerate()

enumerate(Traversable object, start=0)

Note: the start parameter is used to set the starting value of the subscript of traversal data, which is 0 by default.

list1 = ['a', 'b', 'c', 'd', 'e']

for i in enumerate(list1):
    print(i)

for index, char in enumerate(list1, start=1):
    print(f'The subscript is{index}, The corresponding character is{char}')

4.3 container type conversion

tuple()
Convert a sequence into tuples

list1 = [10, 20, 30, 40, 50, 20]
s1 = {100, 200, 300, 400, 500}

print(tuple(list1))
print(tuple(s1))

list()
Convert a sequence into a list.

t1 = ('a', 'b', 'c', 'd', 'e')
s1 = {100, 200, 300, 400, 500}

print(list(t1))
print(list(s1))

set()
Convert a sequence into a set.

list1 = [10, 20, 30, 40, 50, 20]
t1 = ('a', 'b', 'c', 'd', 'e')

print(set(list1))
print(set(t1))

Keywords: Python data structure

Added by tobias on Sat, 26 Feb 2022 13:20:39 +0200

Programming VIP

07 Python common data structures

1. Sequence

1.1 string

1.1.1 create string

1.1.2 string input and output

1.1.3 subscript

1.1.4 slicing

1.1.5 common operation methods

1.1.5.1 search

1.1.5.2 modification

1.1.5.3 judgment

1.2 tuples

1.2.1 creating tuples

1.2.2 common operations

1.3 list

1.3.1 create list

1.3.2 common operations of list

1.3.2.1 search

subscript

function

Judge whether it exists

1.3.2.2 add

1.3.2.3 delete

1.3.2.4 modification

1.3.2.5 copying

1.3.3 list loop traversal

1.3.4 list nesting

2. Mapping

2.1 dictionary

2.1.1 create dictionary

2.1.2 common operations of dictionary

2.1.2.1 add

2.1.2.2 delete

2.1.2.3 modification

2.1.2.4 check

2.1.3 dictionary loop traversal

3. Set

3.1 creating collections

3.2 common operation methods of collection

3.2.1 add

3.2.2 delete

3.2.1 check

4. Public operation

4.1 operators

4.2 public methods

4.3 container type conversion

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