. NET Programmer's Python basic tutorial learn----lists and tuples [first day]

A. General sequence operation:

In fact, for lists, tuples belong to serialized data, which can be accessed through the following table. Let's take a look at the basic operation of the sequence below.

1.1 Index:

The subscript of all elements in the sequence is incremented from 0. If the length of the index is N, then the range is between-n~n-1, and exceeding this range will prompt indexerror:index out of range

>>> greeting ='HelloWorld'print  greetinghelloWorldPrint greeting[0],greeting[-1]h D

1.2 Shards:

A. Simple shards:
Sharding is based on an index and can be understood as taking a certain area of data, similar to substring in C #, and the Skip () and take () methods provided by C#LINQ.

NOTE:[A:B] A, A and b respectively corresponding to the index subscript, the value area is [A, b] (learned that the math is not included in the C). Note that the opinion is that B must be greater than a, otherwise the output is empty, then the problem is why Web[9:-1] have data, please think carefully, actually-1 of the subscript data equivalent to M subscript 12,12>9 so there is data. Then for WEB[9:-5] it's tragic.

>>> Web ='www.baidu.com'print web[4:9] #4对于的bbaiduPrint web[9:-5
print web[9:-1]  #9对应的第二个 '. '  -1 corresponding m.co

B. Shards in arithmetic progression form:

By default, when the index interval is 1, it can be further segmented by a third parameter. [A:B: Interval number], 10 digits not two take 1 times.

　　

>>> number =[1,2,3,4,5,6,7,8,8,10]print number[0:10:2[1, 3, 5, 7, 8]
>>> Print Number[::-2]
[10, 8, 6, 4, 2]
>>> Print Number[::2]
[1, 3, 5, 7, 8]

1.3 Sequence Additions:

The same type of can want to add, different types of errors will be error type error

>>> [4,5] + [][1, 2, 3, 4, 5]>>> [+[]'Hello'][1, 2, 3,'Hello']>>> [1,2,3]+'Hello'Traceback (most recent): File"<pyshell#41>", Line 1,inch<module>    [1,2,3]+'Hello'Typeerror:can only concatenate list ( not "Str") to list>>>

1.4 Multiplication:
I think the multiplication of Python is interesting and can be understood as a multiple copy of the existing data.

　　　　

>>> [1]*10[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]'*10'
    '

1.5 useful methods.

Through in can check whether the element exists, Max,min,len,count get the maximum value, the minimum value, the length, including the quantity

　　　　

>>> number =[1,2,2,3,3,4,5,7]print'max number:' + str (max (number)) Max Number:The quantity ofprint'2 is:' + str (number.count (2)) 2 is:  The length of the print ' number list is:' + str ' (len number) The length of the number list is:8

Two. List.
　　

The list can be understood as a linked table in C. or C # List<object>, the list can be implemented above the common serial number operation, can be added to the list, delete, change, check, sorting and other methods

2.1 Basics of Lists

>>>PrintList'123')#" " can convert a string to a list['1','2','3']>>> list1=[1,2,3]#through the [] Declaration list>>> list2 = list (123)#123 is plastic, there is no index, so when the conversion error. Traceback (most recent): File"<pyshell#53>", Line 1,inch<module>List2= List (123) TypeError:'int'Object is  notIterable

2.2 Basic operations of the list
A increase, delete, change

>>> numbers =[1,2,3,4,5]>>> numbers[0]=5;#Modify>>>Printnumbers[5, 2, 3, 4, 5]>>> Numbers.remove (5)#Remove the value of 5>>>Printnumbers[2, 3, 4, 5]>>>delNumbers[0]#Delete First element>>>Printnumbers[3, 4, 5]>>> Numbers.append (7)#add an element to the tail>>>Printnumbers[3, 4, 5, 7]

B Shard Assignment "magical shard operation"

Overall replacement
　　　　

>>> greeting= [1,2,3,4,5]
>>> greeting[1:] = [0,0]
>>> Greeting
[1, 0, 0]

Replacement interval

>>> greeting= [1,2,3,4,5]>>> greeting[1:2]=[0,0,0]>>> greeting[ 1, 0, 0, 0, 3, 4, 5]

Batch add, replace with [0,0,0] []

>>> greeting=[1,2,3,4,5]>>> greeting[1:1]=[0,0,0]>>> greeting[ 1, 0, 0, 0, 2, 3, 4, 5]

Bulk Delete, replace [2,3,4] with []

>>> greeting=[1,2,3,4,5]>>> greeting[1:4]=[]>>> greeting[1, 5]

Note: For various operations can be understood as a replacement.

2.3 List of methods.

>>> number =[1,2,3,4,5]>>> number.extend ([6,7,8])#Add a list that must be a list>>>number[1, 2, 3, 4, 5, 6, 7, 8]>>> Names =['Frank','Lock','Vincent','Tingna']>>> Names.index ('Lock')#remove the label by index1>>> Names.insert (2,'Hardy')>>>names['Frank','Lock','Hardy','Vincent','Tingna']>>> Names.pop ()#most one element is deleted'Tingna'>>>names['Frank','Lock','Hardy','Vincent']>>> Names.pop (0)#kick out the first element'Frank'>>>names['Lock','Hardy','Vincent']>>> Names.reverse ()#reverse Order>>>names['Vincent','Hardy','Lock']>>> Names.sort ()#从小到达>>>names['Hardy','Lock','Vincent']>>> Names.sort (Key=len)#Sort by length>>>names['Lock','Hardy','Vincent']>>> Names.sort (reverse=true)#从大到小>>>names['Vincent','Lock','Hardy']

Three. Tuples immutable sequences

With the () sign, the difference from list is that it is immutable once declared.
　　　　

 >>> tuple1 = (1,2,3)  >>> 1, 2, 3)  >>> tuple (list ( '  ,  '  e   ' ,  '  l   ' ,  '  l   ' ,  '  o   '   '  >>> 

Four. Summary
　　　　

     This chapter summarizes the list and tuples in the basic Python tutorial, but the overall difference between. NET is not too big. For example, a wonderful slicing operation is actually simplifying the addrang,revomeall of. Net. Indeed, as the book says, Python can use 100 lines of code to do what the C-language 1000 line of code needs to do.             All right, wash and sleep. For tomorrow the company annual meeting can draw the iphone local Tyrants Gold Award, hahaha.
     [Take advantage of one months of working out of the Python basic tutorial, complete the Basic Tutorial Learning Blog series. Come on!]

. NET Programmer's Python basic tutorial learn----lists and tuples [first day]