str1 = "2000a200b20c"

I want to use regular expression to split this string and I hope the result like,

["2000a","200b","20c"]

I tried to

import re
print(re.split(r'([a-z])',str1)

but it shows,

["2000","a","200","b","20","c",""]

I have two question,how to combine the character with previous one and why there is always a blank in end of list?

CodePudding user response：

I would use a regex find all approach here:

str1 = "2000a200b20c"
parts = re.findall(r'\d [a-z] ', str1, flags=re.I)
print(parts)  # ['2000a', '200b', '20c']

CodePudding user response：

If you want to use split, you can use the following:

import re
str1 = "2000a200b20c"
re.split( '(?<=[a-z])(?=\d)' , str1)

This says that you need to split at a point that is

1. preceded by a character '(?<=[a-z])', and
2. followed by a number '(?=\d)'

You should review the look-ahead and look-back parts of regular expressions.