使用 python 正则表达式匹配整个字符串变量

Question

I am new to python.

I want to write a regex to find a whole string using re.match.

For example,

word1=I 
word2=U
str_to_match = word1+"[There could be some space in between]"+  word2[this is the end of string I want to match]"

In this case, it should match I[0 or more spaces in between]U . It shouldn't match abI[0 or more spaces in between]U , OR abI[0 or more spaces in between]Ucd , OR I[0 or more spaces in between]Ucd .

I know you could use boundary \b to set the word boundary but since there could be a number of spaces in between word1 and word2, the whole string is like a variable, not a fixed string, it won't work for me:

ret=re.match(r"\b"+word1+r"\s+" +word2+r"\b")

not working

Does anyone know how could I find the correct way to match this case? Thanks!

Answer 1

match only matches at the beginning of the string . Which since you are using \b should not be what you want. findall will find all matching strings.
If you want to find the first occurrence and just test if it exists in the string, and not find all matches you can use search :

word1 = 'I'
word2 = 'U'
ret = re.findall(rf"\b{word1}\s*{word2}\b"," I   U  IU  I  U  aI U I Ub")
print(ret)
ret = re.search(rf"\b{word1}\s*{word2}\b"," IUb  .I    U ")
print(ret)