Python string operation implementation code of interception and replace and find and segmentation

Python intercepts strings by using a variable [header subscript: tail subscript], which intercepts the corresponding string, where the subscript starts at 0 and can be positive or negative, and the subscript can be null for the header or tail.

#  case 1 : string interception 
str = '12345678'
print str[0:1]
>> 1   #  The output str location 0 Start to position 1 Previous character 
print str[1:6]  
>> 23456   #  The output str location 1 Start to position 6 Previous character 
num = 18
str = '0000' + str(num) #  Merge string 
print str[-5:]  #  Output string right 5 position 
>> 00018   

Python replaces strings with variables. Replace (" replaced content ", "replaced content "[, number of times]), and the number of times can be null. Note that the replace string is only temporary and needs to be re-assigned to save.

#  case 2 : string replacement 
str = 'akakak'
str = str.replace('k',' 8') #  I'm going to put in the string k Replace them all with 8
print str
>> 'a8a8a8'  #  The output 

Python USES variables to find strings. Find (" what to find "[, start position, end position]), start position and end position indicate the range to be found, and null indicates all. If found, the position will be returned, starting from 0. If found, the position will return -1.

#  case 3 : string lookup 
str = 'a,hello'
print str.find('hello') #  In a string str Find a string in hello
>> 2   #  The output 

Python splits strings using variables. Split (" split token "[split number]), split number means the maximum number of split, is empty then split all.

Example 4: character segmentation

str = 'a,b,c,d'
strlist = str.split(',') #  Split with a comma str String and save it to the list 
for value in strlist: #  The loop outputs the list values 
    print value
>> a   #  The output 
>> b
>> c
>> d