Summary of python string processing functions

str='python String function'

Generate string variable str='python String function'

Get the string length: len(str)

Example: print '%s length=%d' % (str,len (str))

1. Letter processing

All uppercase: str.upper()

All lowercase: str.lower()

Case swap: str.swapcase()

The first letter is capitalized, the rest is lowercase ：str.capitalize()

Capitalize the first letter: str.title()

print '%s lower=%s' % (str,str.lower())

print '%s upper=%s' % (str,str.upper())

print '%s swapcase=%s' % (str,str.swapcase())

print '%s capitalize=%s' % (str,str.capitalize() )

Print '%s title=%s' % (str,str.title())

2. Formatting related

Get a fixed length, right-aligned, and fill in spaces if there is not enough space on the left: str.ljust(width )

Get a fixed length, aligned to the left, and fill in spaces if the right side is not enough: str.ljust(width)

Get a fixed length, aligned in the middle, fill in spaces if there are not enough spaces on both sides: str.ljust(width)

Get a fixed length , right-aligned, fill in the left part with 0s

print '%s ljust=%s' % (str,str.ljust(20))

print '%s rjust=%s' % (str,str.rjust (20))

print '%s center=%s' % (str,str.center(20))

print '%s zfill=%s' % (str,str.zfill(20))

3. String search related

Search for the specified string, no -1 is returned: str.find('t')

Specify the starting position to search: str.find('t',start)

Specify Start and end position search: str.find('t',start,end)

Search from the right: str.rfind('t')

How many specified strings are searched: str.count('t ')

All the above methods can be replaced by index. The difference is that if index is not found, an exception will be thrown, and find returns -1

print '%s find nono=%d' % (str,str.find(' nono'))

print '%s find t=%d' % (str,str.find('t'))

print '%s find t from %d=%d' % (str,1, str.find('t',1))

print '%s find t from %d to %d=%d' % (str,1,2,str.find('t',1,2))

#print '%s index nono ' % (str,str.index('nono',1,2))

print '%s rfind t=%d' % (str,str.rfind('t' ))

Print '%s count t=%d' % (str,str.count('t'))

4. String replacement related

Replace old with new: str.replace(' old','new')

Replace the specified number of times old with new: str.replace('old','new',maxReplaceTimes)

print '%s replace t to *=%s' % (str,str .replace('t', '*'))

print '%s replace t to *=%s' % (str,str.replace('t', '*',1))

5. Remove spaces and specified characters from a string

Remove spaces on both sides: str.strip()

Remove spaces on the left: str.lstrip()

Remove spaces on the right: str.rstrip()

Remove strings on both sides: str.strip('d'), corresponding to lstrip, rstrip

str=' python String function '

print '%s strip=%s' % (str,str.strip())

str=' python String function'

print '%s strip=%s' % (str,str.strip('d'))

6. Split the string into an array by specified characters: str.split(' ' )

Default separated by spaces

str='a b c de'

print '%s strip=%s' % (str,str.split())

str='a-b-c-de'

print '% s strip=%s' % (str,str.split('-'))

7. String judgment related

Whether it starts with start: str.startswith('start')

Whether it starts with end Ending: str.endswith('end')

Whether it is all letters or numbers: str.isalnum()

Whether it is all letters: str.isalpha()

Whether it is all numbers: str.isdigit()

Whether it is all Lowercase: str.islower()

Whether all uppercase: str.isupper()

str='python String function'

print '%s startwith t=%s' % (str,str.startswith('t' ))

print '%s endwith d=%s' % (str,str.endswith('d'))

print '%s isalnum=%s' % (str,str.isalnum())

str='pythonStringfunction'

print '%s isalnum=%s' % (str,str.isalnum())

print '%s isalpha=%s' % (str,str.isalpha())

   print '%s isupper=%s' % (str,str.isupper())

   print '%s islower=%s' % (str,str.islower())

   print '%s isdigit=%s' % (str,str.isdigit())

   str='3423'

   print '%s isdigit=%s' % (str,str.isdigit())