Python Learning Urllib Module---for sending network requests, getting data (2)

followed by the last content.

Let's start with the Split () method: It slices the string by specifying a delimiter, and if the parameter num has a specified value, it separates only the NUM substring (a list that splits a string into a number of strings)

Syntax:str. Split(str="", num=string. Count(str)).

< span class= "str" >< Span class= "PLN" >                                parameter: str delimiter, default is a space. Num Split count

< span class= "str" >< Span class= "PLN" >                               return value: Returns the segmented list of strings

< span class= "str" >< Span class= "PLN" >                               For example: you need to take each word in an English sentence out of the box, and you can split it.

< span class= "str" >< Span class= "PLN" >                                        such as: A= ' I am a new student '

< span class= "str" >< Span class= "PLN" >                                             A.split ()  

< span class= "str" >< Span class= "PLN" >                                             Split splits the string into spaces, all of which are new strings, and eventually return a list of strings,

< span class= "str" >< Span class= "PLN" >                                             Results [' I ', ' am ', ' a ', ' new ', ' student ']

< span class= "str" >< Span class= "PLN" >                                             In fact, the split () method is very similar to the delimiter in Excel.

< span class= "str" >< Span class= "PLN" >                                it corresponds to the method join () that joins the list string, which is to concatenate all the strings in the list into a string

                                such as: s= ', '    lis= [' I ', ' am ', ' A ', ' new ', ' Student ']   result=s.jion (LIS)      print result          get results for ' i,am,a,new,student '

< span class= "str" >< Span class= "PLN" >                                Press, connect list           

< span class= "str" >< Span class= "PLN" >                               list can traverse the elements in the LIS with for...in.    for I in rang (1,10) here rang (1,10) is a list  [1,2,3,4,5,6,7,8,9] 

< span class= "str" >< Span class= "PLN" >                               I=rang (1,10) =[1,2,3,4,5,6,7,8,9],  for i in I: And for i  in Rang (1,10): The effect is the same.

< span class= "str" >< Span class= "PLN" >                               explain how to manipulate list List

< span class= "str" >< Span class= "PLN" >                               1 "Access to elements in list    as above print lis[0] will output ' I '

2 "Modify the list of elements such as modify the above lis,lis[4]= ' teacher ', the output of the LIS when the last element was changed to ' teacher '

3 "list add element with Append method such as Lis.append (2016)

4 "Delete list element with Del method, e.g. Del[4]

Ah, said so much, in fact, the feeling is not what the use of rice, in fact, these are the basic knowledge, today, I review it again, because crawling the content of the network is often to manipulate the list drop. With this in view, you can continue learning to capture the province/municipality number today.

Yesterday's study is how to get a network resource information, which is similar to the file operation, is open, and then read, decode, split into a list of the steps. You can use this code directly

B=urllib.request.urlopen (' Http://m.weather.com.cn/data5/city.xml '). Read (). Decode (). Spilt (', ')

This allows you to get a list of B, which is what the above print prints. Analysis, we have to get the data 01, 02, we have to manipulate this B-list

Here's a list of the B's to be manipulated, try

Print (b[0]) Look, is it printed out ' 01| Beijing '? To continue the analysis, at this time b[0] is also a string, it will be divided according to |, you can draw 01, so the operation is as follows, should be b[0].spilt (' | ') , the split data should be [01, ' Beijing '], at this time again value: B[0].split (' | ') [0]? The idea is this, see if it is?

One is to do so, and the same is the same as the loop, so you have to use the for I in list

For i in B: #i =b[0],b[1],b[2] ...

Code=i.split (' | ') [0]

web= ' http://m.weather.com.cn/data5/city%s '

Web1=web%code

Print (WEB1)

See if I can print out the data for the second interface? Of course, if you feel too much, you can only play two or three provinces to see. For I in B[:2]

Well, it's a little late, and tomorrow, September 1, 2016.

Python Learning Urllib Module---for sending network requests, getting data (2)