Checking if string starts the same but end differently using re module

[ranbarr]

Hi!
Im learning the re module and having a difficulties with the writing of it so Ill be happy to have some explanations.
I have a file with a lot of columns, and I try to find if its first column starts the same at all the rows but end with different range of numbers.
Example of the columns:

chr10
chr10
chr10
chr11
chr11
chr12
chr15
chr17
chr18
chrX
chrX
chr10
chr10
chr10
chr11
chr11
chr12
chr15
chr17
chr18
chrX
chrX
chr10
chr10
chr10
chr11
chr11
chr12
chr15
chr17
chr18
chrX
chrX
chr10
chr10
chr10
chr11
chr11
chr12
chr15
chr17
chr18
chrX
chrX

what I'm trying to do is to find if all the strings start with "chr" and ends with the range of 1-99 or "X" or "Y" or "M".

so I tried to do something like that:

with open("vcf1.vcf", "r+") as my_file:
        lines = my_file.readlines()
        for line in lines:
            columns = line.split("\t")
            if re.match(r"^chr([1-9][0-9]|[X]|[Y]|[M]?)$", columns[0]):
                print(True)

which return as output:

True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True
True

thats the output I should get but I dont feel like I did in the right way and its only considering the chr and not the rest.
appreciate any kind of help!

[Gribouillis]

I don't see why M is optional. I would use

r"^chr(?:[1-9][0-9]|[XYM])$"

Note that this matches only the range 10-99, not 1-99. If you want 1-99, you can use

r"^chr(?:[1-9][0-9]?|[XYM])$"

You could write a few unit tests for the regex.