如何从句子中删除数字和长度小于 2 的单词？

Question

I am trying to remove words that have length below 2 and any word that is numbers. For example

 s = " This is a test 1212 test2"

Output desired is

" This is test test2"

I tried \\w{2,} this removes all the word whose length is below 2. When I added \\D+ this removes all numbers when I didn't want to get rid of 2 from test2 .

Answer 1

You may use:

s = re.sub(r'\b(?:\d+|\w)\b\s*', '', s)

RegEx Demo

Pattern Details:

• \\b : Match word boundary
• (?:\\d+|\\w) : Match a single word character or 1+ digits
• \\b : Match word boundary
• \\s* : Match 0 or more whitespaces

Answer 2

You can make use of work boundaries '\\b' and remove anything that is 1 character long inside boundaries: number or letter, doesn't matter. Also remove anything between boundaries that is just numbers:

import re

s = " This is a test 1212 test2"

print( re.sub(r"\b([^ ]|\d+)\b","",s))

Output:

 This is  test  test2

Explanation:

\b(           word boundary followed by a group
   [^ ]           anything that is not a space (1 character) 
       |              or
        \d+       any amount of numbers
)             followed by another boundary

is replaced by re.sub(pattern, replaceBy, source) with "" .

Answer 3

Maybe (?i)\\b(?:\\d+|[az])\\b[ \\t]*
https://regex101.com/r/bnS15k/1

Does some wsp trimming.

---

Whitespace trimming is probably more important for these kind of things.
This modded version does it from both sides.

Just subs it using
(?im)(?:([ \\t])+\\b(?:\\d+|[az])\\b[ \\t]*[ \\t]*|^\\b(?:\\d+|[az])\\b[ \\t]*[ \\t]*())
With replace \\1\\2

https://regex101.com/r/gSswPe/1
Strips wsp from both sides.

 (?im)
 (?:
    ( [ \t] )+           # (1)
    \b 
    (?: \d+ | [a-z] )
    \b [ \t]* [ \t]* 
  | 
    ^ \b 
    (?: \d+ | [a-z] )
    \b [ \t]* [ \t]* 
    ( )                  # (2)
 )

Answer 4

You can do it like that:

import re

s = " This is a test 1212 test2"

p = re.compile(r"(\b(\w{0,1})\b)|(\b(\d+)\b)")

result = p.sub('', s)

print(result)

Output:

" This is  test  test2"

I noticed that your desired output does not contain consecutive whitespaces. If you want to replace consecutive whitespaces by one, you can do this:

p = re.compile(r"  +")
result = p.sub(' ', result)

Output:

" This is test test2"

(\\b(\\w{0,1})\\b) this group matches words with length up to 1 (included)

(\\b(\\d+)\\b) this group matches word composed of digit(s) only

| The pipe means "or", so this expression will match either group 1 or group 2

\\b It's the "word boundary". By surrounding some regex with "\\b", it will match "whole words only"

\\w It will match wharacters supposed to part of a word

\\d+ This means "at least one digit or more"

Note that what \\b and \\w will match will depends on the regex flavor you are using.

Answer 5

Just to put my two cents in - you could use the inbuilt string functions:

s = " This is a test 1212 test2"
result = " ".join(word for word in s.split() 
                  if len(word) >= 2 and not word.isdigit())
print(result)

Which would yield

This is test test2