/*! Ads Here */

List of tuples Python Mới nhất

Thủ Thuật về List of tuples Python Chi Tiết


Bạn đang tìm kiếm từ khóa List of tuples Python được Update vào lúc : 2022-01-07 14:21:08 . Với phương châm chia sẻ Kinh Nghiệm Hướng dẫn trong nội dung bài viết một cách Chi Tiết Mới Nhất. Nếu sau khi Read tài liệu vẫn ko hiểu thì hoàn toàn có thể lại phản hồi ở cuối bài để Ad lý giải và hướng dẫn lại nha.


List and Tuple are built-in container types defined in Python. Objects of both these types can store different other objects that are accessible by index. List as well as tuple is a sequence data type, just as string. List as well as tuple can store objects which need not be of same type.


Nội dung chính


  • Difference between List and Tuple:

  • Conversion functions


  • List : A List is an ordered collection of items (which may be of same or different types) separated by comma and enclosed in square brackets.


    In [1]:

    L1=[10,25.5,3+2j,”Hello”]

    L1

    Out[1]:

    [10, 25.5, (3+2j), ‘Hello’]


    In above list, each item is of different type. Further, each item is accessible by positional index starting from 0. Hence L1[2] will return 25.5


    In [2]:

    L1[1]

    Out[2]:

    25.5


    Tuple: Tuple looks similar to list. The only difference is that comma separated items of same or different type are enclosed in parentheses. Individual items follow zero based index, as in list or string.


    In [3]:

    T1=(10,25.5,3+2j,”Hello”)

    T1

    Out[3]:

    (10, 25.5, (3+2j), ‘Hello’)

    In [4]:

    T1[1]

    Out[4]:

    25.5


    Difference between List and Tuple:


    The obvious difference is the use of square brackets [] in List and parentheses () in tuple as enclosures. However, the important difference is that List as a mutable object and Tuple is an immutable object.


    If contents of an object can be modified in place, after it has been instantiated, is a mutable object. On the other hand, any operation on immutable object that tries to modify its contents is prohibited.


    In above example, any item in the list L1 can be assigned with different value. Let us change value of item index=2 from 3+2j to 1.22E-5


    In [5]:

    L1[2]=1.22E-5

    L1

    Out[5]:

    [10, 25.5, 1.22e-05, ‘Hello’]


    The built-in List class has different methods that allow various operations on List object (such as insertion, deletion, sorting etc)


    However, any such operation is not possible with Tuple object. If we try to modify T1 by changing value of item index=2 to 1.22E-5, TypeError exception is raised.


    In [6]:

    T1[2]=1.22E-5

    T1

    —————————————————————————

    TypeError Traceback (most recent call last)

    in ()

    —-> 1 T1[2]=1.22E-5

    2 T1

    TypeError: ‘tuple’ object does not tư vấn item assignment


    Following built-in functions can be used along with List as well as Tuple.


    len()Returns number of elements in list/tuplemax()If list/tuple contains numbers, largest number will be returned. If list/tuple contains strings, one that comes last in alphabetical order will be returned.min()If list/tuple contains numbers, smallest number will be returned. If list/tuple contains strings, one that comes first in alphabetical order will be returned.sum()Returns addition of all elements in list/tuplesorted()sorts the elements in list/tupleIn [7]:

    L1=[10,30,50,20,40]

    T1=(10,50,30,40,20)

    print (len(L1))

    print (len(T1))

    print (‘max of L1’, max(L1))

    print (‘max of T1’, max(T1))

    print (‘min of L1’, min(L1))

    print (‘min of T1’, min(T1))

    print (‘sum of L1’, sum(L1))

    print (‘sum of T1’, sum(T1))

    print (‘L1 in sorted order’, sorted(L1))

    print (‘T1 in sorted order’, sorted(T1))

    Out[7]:

    5

    5

    max of L1 50

    max of T1 50

    min of L1 10

    min of T1 10

    sum of L1 150

    sum of T1 150

    L1 in sorted order [10, 20, 30, 40, 50]

    T1 in sorted order [10, 20, 30, 40, 50]


    If items in list/tuple are strings, min() and max() functions returns string that comes first/last in alphabetical order. If list/tuple is made up of numeric and nonnumeric values, TypeError exception is raised as comparison of dissimilar objects is not possible.


    In [8]:

    L2=[‘pen’, ‘book’,’computer’, ‘table’, ‘file’]

    T2=(‘pen’, ‘book’,’computer’, ‘table’, ‘file’)

    print (‘max of L2’, max(L2))

    print (‘max of T2’, max(T2))

    print (‘min of L2’, min(L2))

    print (‘min of T2’, min(T2))

    max of L2 table

    max of T2 table

    min of L2 book

    min of T2 book

    Out [9]:

    L3=[100, “hundred”, 0.001]

    print (‘max of L3’, max(L3))

    —————————————————————————

    TypeError Traceback (most recent call last)

    in ()

    1 L3=[100, “hundred”, 0.001]

    —-> 2 print (‘max of L3’, max(L3))

    TypeError: ‘>’ not supported between instances of ‘str’ and ‘int’


    The built-in list class has following methods to perform various operations on list object. Following methods allow new items to be added to list.


    append()appends an object to end of listcopy()makes a shallow copy of list count()return number of occurrences of value in listextend()extends the list by appending elements from another list/tuple insert()inserts object in the list before given index In [10]:

    L1=[10,30,50,20,40]

    L1.append(100) #appends new item

    print (“after append”,L1)

    L1.insert(2,30) #inserts new value index

    print (‘after insert’,L1)

    c=L1.count(30)

    print (‘count of 30’,c)

    L1.extend([11,22,33])

    print (‘after extend’, L1)

    Out [10]:

    after append [10, 30, 50, 20, 40, 100]

    after insert [10, 30, 30, 50, 20, 40, 100]

    count of 30 2

    after extend [10, 30, 30, 50, 20, 40, 100, 11, 22, 33]


    Following methods are used to remove items from given list.


    pop()removes and returns item given index . Raises IndexError if list is empty or index is out of range.remove()removes first occurrence of value in the list. Raises ValueError if the value is not present.clear()remove all items from the listIn [11]:

    p.=L1.pop()

    print(‘item popped:’, p.)

    print(‘list after popping’, L1)

    L1.remove(100)

    print(‘after removing value :’,L1)

    L1.clear()

    print(‘all cleared:’, L1)

    Out[11]:

    item popped: 33

    list after popping [10, 30, 30, 50, 20, 40, 100, 11, 22]

    after removing value : [10, 30, 30, 50, 20, 40, 11, 22]

    all cleared: []


    Following methods rearrange sequence of items in the list


    reverse()reverses the list in placesort()sorts the list in placeIn [12]:

    L1=[10, 30, 30, 50, 20, 40, 11, 22]

    print (‘original list :’, L1)

    L1.reverse()

    print (‘after reversing:’,L1)

    L1.sort()

    print (“sorted list: “, L1)

    Out [12]:

    original list : [10, 30, 30, 50, 20, 40, 11, 22]

    after reversing: [22, 11, 40, 20, 50, 30, 30, 10]

    sorted list: [10, 11, 20, 22, 30, 30, 40, 50]


    If you recall, tuple is an immutable object. Hence the tuple class doesnt have similar methods perform insertion, deletion or rearrangement of items.


    Conversion functions


    All sequence type objects (string, list and tuple) are inter-convertible. Pythons built-in functions for this purpose are explained below:


    list()converts a tuple or string to listtuple()converts list or string to tuplestr()returns string representation of list or tuple objectIn [13]:

    L1=[10, 30, 30, 50, 20, 40, 11, 22]

    T1=tuple(L1)

    print (T1)

    (10, 30, 30, 50, 20, 40, 11, 22)

    In[14]:

    T1=(10,50,30,40,20)

    L1=list(T1)

    print (L1)

    [10, 50, 30, 40, 20]

    In [15]:

    s1=”Hello”

    L2=list(s1)

    print (‘string to list:’, L2)

    T2=tuple(s1)

    print (‘string to tuple’, T2)

    string to list: [‘H’, ‘e’, ‘l’, ‘l’, ‘o’]

    string to tuple (‘H’, ‘e’, ‘l’, ‘l’, ‘o’)

    In [16]:

    s1=str(L1)

    s2=str(T1)

    print (‘list to string’,s1)

    print (‘tuple to string’,s2)

    list to string [10, 50, 30, 40, 20]

    tuple to string (10, 50, 30, 40, 20)


    When a list or tuple is converted to string by str() function, the string representation is not exactly similar to word, but list or tuple surrounded by single quote marks. To form a continuous sequence of characters in the list, use join() method of string object.


    In [17]:

    L2=[‘H’, ‘e’, ‘l’, ‘l’, ‘o’]

    s1=str(L2)

    s1

    Out[17]:

    “[‘H’, ‘e’, ‘l’, ‘l’, ‘o’]”

    In [18]:

    s2=””.join(L2)

    print (‘string from list items:’, s2)

    string from list items: Hello


    In this chapter, we discussed the list and tuple objects, their functions and methods. In next chapter we shall learn about dictionary data type.


    Reply

    6

    0

    Chia sẻ


    Share Link Download List of tuples Python miễn phí


    Bạn vừa đọc Post Với Một số hướng dẫn một cách rõ ràng hơn về Video List of tuples Python tiên tiến và phát triển nhất ShareLink Download List of tuples Python miễn phí.



    Hỏi đáp vướng mắc về List of tuples Python


    Nếu sau khi đọc nội dung bài viết List of tuples Python vẫn chưa hiểu thì hoàn toàn có thể lại Comment ở cuối bài để Ad lý giải và hướng dẫn lại nha

    #List #tuples #Python

*

Đăng nhận xét (0)
Mới hơn Cũ hơn

Responsive Ad

/*! Ads Here */

Billboard Ad

/*! Ads Here */