Python Sequence--list

• • What is a list?
    • 1 Creating a list
    • 2 access list and update list
  • List-related actions
  • Support for lists in built-in functions
    • 1 CMP
    • 2 Sequence type functions
  • List built-in functions
  • List application
    • 1 stacks
    • 2 queues

1. What is a list?

Lists are also one of the sequences. Lists can hold any number of Python objects, and the list is a mutable type.

1.1 Creating a list

The list can be created using [], or by using the Factory method list ().

>>> t = list()>>> ‘list‘>>>> l = []>>> ‘list‘>>>> t == lTrue

1.2 Access list and update list

>>>t = List (' Furzoom ')>>>t[' F ',' u ',' R ',' Z ',' O ',' O ',' m ']>>>t[1]' u '>>>t[2] =' n '>>>t[' F ',' u ',' n ',' Z ',' O ',' O ',' m ']>>>T.append ('. ')>>>t[' F ',' u ',' n ',' Z ',' O ',' O ',' m ','. ']>>>delt[3]>>>t[' F ',' u ',' n ',' O ',' O ',' m ','. ']>>>delT>>>Ttraceback (most recent): File"<stdin>", line1,inch<module>nameerror:name' t '  is  notDefined

2. List-related actions

Support comparison operation, slice [] or [:], in, not in, join operator +, repeat operation.

If possible, use the List.extend () method instead of the connection operator.

The list also supports very important list resolution operations.

>>> forin xrange(10)][0123456789]

3. Built-in function support for lists 3.1 CMP ()

Comparison principle:

1. Compares the elements of a two list.
2. If the element being compared is of the same type, the value is compared and the result is returned.
3. If two elements are not of the same type, check whether they are numbers.
   3.1 If it is a number, perform the necessary number to force the type conversion, and then compare.
   3.2 If one of the elements is a number, the other party's element is large.
   3.3 Otherwise, the alphabetical order of the type name is compared.
4. If there is a list that reaches the end first, the other longer list is larger.
5. If all two lists reach the end and all elements are equal, 0 is returned.

3.2 Sequence type functions

• Len ()
• Max ()
• Min ()
• Sorted ()
• Reversed ()
• Enumerate ()
• Zip ()
• SUM ()
• List ()
• Tuple ()

4. List built-in functions

• List.append (x)
• List.extend (x)
• List.count (x)
• List.index (x[, start[, end]])
• List.insert (index, X)
• List.pop ([index])
• List.remove (x)
• List.remove ()
• List.sort ([cmp[, key[, reverse]])

5. List Apply 5.1 stacks

#!/usr/bin/env python#-*-Coding:utf-8-*-stack = [] def pushit():Stack.append (Raw_input (' Enter New string: '). Strip ()) def popit():    ifLen (stack) = =0:Print ' cannot pop from an empty stack! '    Else:Print ' Removed [', ' Stack.pop () ','] ' def viewstack():    PrintStackcmds = {' u ': Pushit,' O ': Popit,' V ': Viewstack} def showmenu():PR ="" " p (U) SH p (O) p (V) iew (Q) uit Enter choice: " "     while True: while True:Try: Choice = raw_input (pr). Strip () [0].lower ()except(Eoferror, Keyboardinterrupt, indexerror): choice =' Q '            Print ' \nyou picked: [%s] '% ChoiceifChoice not inch ' Uovq ':Print ' Invalid option, try Again '            Else: Break        ifChoice = =' Q ': BreakCmds[choice] ()if__name__ = =' __main__ ': ShowMenu ()

The following example runs:

P (U) SH p (O) p (V) iew (Q) uitEnterChoice:uyou picked: [u]EnterNew String:python P (U) SH p (O) p (V) iew (Q) uitEnterChoice:uyou picked: [u]EnterNew String:is P (U) SH p (O) p (V) iew (Q) uitEnterChoice:uyou picked: [u]EnterNew string:cool! P (U) SH p (O) p (V) iew (Q) uitEnterChoice:vyou picked: [v][' Python ',' is ',' cool! '] P (U) SH p (O) p (V) iew (Q) uitEnterChoice:oyou picked: [O]removed[' cool! '] P (U) SH p (O) p (V) iew (Q) uitEnterChoice:oyou picked: [O]removed[' is '] P (U) SH p (O) p (V) iew (Q) uitEnterChoice:oyou picked: [O]removed[' Python '] P (U) SH p (O) p (V) iew (Q) uitEnterChoice:oyou picked: [O]cannot pop from an empty stack! P (U) SH p (O) p (V) iew (Q) uitEnterChoice: ^DYou picked: [Q]

5.2 Queues

#!/usr/bin/env python#-*-Coding:utf-8-*-Queue = [] def EnQ():Queue.append (Raw_input (' Enter New string: '). Strip ()) def DeQ():    ifLen (queue) = =0:Print ' cannot pop from an empty queue! '    Else:Print ' Removed [', ' Queue.pop (0)`,'] ' def viewq():    PrintQueuecmds = {' E ': EnQ,' d ': DeQ,' V ': Viewq} def showmenu():PR ="" " (E) nqueue (D) equeue (V) iew (Q) uit Enter choice: " "     while True: while True:Try: Choice = raw_input (pr). Strip () [0].lower ()except(Eoferror, Keyboardinterrupt, indexerror): choice =' Q '            Print ' \nyou picked: [%s] '% ChoiceifChoice not inch ' Edvq ':Print ' Invalid option, try Again '            Else: Break        ifChoice = =' Q ': BreakCmds[choice] ()if__name__ = =' __main__ ': ShowMenu ()

The following example runs:

(E) Nqueue (D) Equeue (V) iew (Q) uitEnterChoice:eyou picked: [E]EnterNew string:bring Out (E) Nqueue (D) Equeue (V) iew (Q) uitEnterChoice:eyou picked: [E]EnterNew String:your dead! (E) Nqueue (D) Equeue (V) iew (Q) uitEnterChoice:vyou picked: [v][' Bring out ',' Your dead! ']    (E) Nqueue (D) Equeue (V) iew (Q) uitEnterChoice:dyou picked: [d]removed[' Bring out ']    (E) Nqueue (D) Equeue (V) iew (Q) uitEnterChoice:dyou picked: [d]removed[' Your dead! ']    (E) Nqueue (D) Equeue (V) iew (Q) uitEnterChoice:dyou picked: [D]cannot pop from an empty queue! (E) Nqueue (D) Equeue (V) iew (Q) uitEnterChoice: ^DYou picked: [Q]

Python Sequence--list