正则表达式：搜索以 @ 或 @ 开头的单词

Question

I want to create a regex in python that find words that start with @ or @.

I have created the following regex, but the output contains one extra space in each string as you can see

regex = r'\s@\/?[\w\.\-]{2,}'
exp = 'george want@to play @.hdgska football @dddada'
re.findall(regex, exp)
Output: [' @.hdgska', ' @dddada']

However, the output that I want to have is the following

Output: ['@.hdgska', '@dddada']

I would be grateful if you could help me!

Edit: @The fourth bird, Thank you so much for your help. There is one more thing that I don't know how to deal with. In case that we have this string

s = "george want@to play @.hdgska football @dddada@snhfbjskjs"

the output is

['@.hdgska', '@dddada']

However, the output that I want should be one this

'@.hdgska'

Answer 1

In your pattern you are actually matching the leading \s and after the @ there can be an optional / with \/? but it should optionally start with a dot.

You could match for example an optional dot, and then 2 or more times the allowed characters in the character class.

At the left of the @ sign, either assert a non word boundary or assert a whitespace boundary.

Note that you don't have to escape the dot and the hyphen in the character class.

\B@\.?[\w.-]{2,}

Regex demo

Another option:

(?<!\S)@\.?[\w.-]{2,}

Regex demo

Example

import re
 
pattern = r"(?<!\S)@\.?\w+[\w.-]{2,}"
s = "george want@to play @.hdgska football @dddada"
print(re.findall(pattern, s))

Output

['@.hdgska', '@dddada']