1. String merging
Use "+" to combine strings, pay attention to adding spaces by yourself.
example:
>>> a='Hello' >>> b= a+ 'There' >>> print(b) HelloThere >>> c=a+' '+'There' >>> print(c) Hello There
2. Use in to make logical judgments
example:
>>> fruit='banana' >>> 'n' in fruit True >>> 'm' in fruit False >>> 'nan' in fruit True >>> if 'a' in fruit: print('Found it') Found it
3. Upper and lower case
Use lower() to lowercase the subtitles of the string, and upper() to uppercase.
example:
>>> greet='Hello Bob' >>> zap=greet.lower() >>> print(zap) hello bob >>> print(greet) Hello Bob >>> print('Hi There'.lower()) hi there
4. Search string
The position of the string starts from 0. Use find() to retrieve the position of the corresponding element, and if it is two adjacent elements, return the position of the starting element.
example:
>>> fruit='banana' >>> pos = fruit.find('na') >>> print(pos) 2 >>> aa = fruit.find('z’） >>> print(aa) -1
5. Retrieve and replace
Use replace() to replace the corresponding element in the string with a specific character.
example:
>>> greet='Hello Bob' >>> nstr=greet.replace('Bob','Jane') >>> print(nstr) Hello Jane >>> nstr=greet.replace('o','X') >>> print(nstr) HellX BXb
6. Remove spaces
Use lstrip() to remove spaces at the beginning of a string, rstrip() to remove spaces at the end of a string, and strip() to remove spaces at the beginning and end.
example:
>>> greet =' Hello Bob ' >>> greet.lstrip() 'Hello Bob ' >>> greet.rstrip() ' Hello Bob' >>> greet.strip() 'Hello Bob'
7. Prefix
Use startswith() to make logical judgments on string prefixes.
example:
>>> line='Please have a nice day' >>> line.startswith('Please') True >>> line.startswith('p') False
8. Decomposition and extraction
Use string slicing and find() to extract the content of the middle part of the string.
example:
>>> data='From [email protected] Sat Jan 5 09:14:16 2008' >>> atpos=data.find('@') >>> print(atpos) 21 >>> sppos=data.find(' ',atpos) >>> print(sppos) 31 >>> host=data[atpos+1:sppos] >>> print(host) uct.ac.za