Using regex for type validation

[ranbarr]

Hi everyone,
I'm stating to learn regex and I'm trying to solve a problem using it.
I need to write a function that gets a file and need to check some columns in the files and see if they stand the requirements.

The first column should start with “chr” and end with any number between 1-99 or one of the letters “M,X,Y”.
Second column need to be all int numbers that are bigger than 0.
4th and 5th columns need to be one of the next letters “ATCG” (only one of them).
If one of the statements are wrong even in one row it should return false.

there's the code I wrote:

def isVCF(file):
        with open(file, "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]?|[XYM])$", columns[0]) 
                and re.match(r"^[1-9][0-9]*$", columns[1])
                and re.match(r"^[ATGC]$", columns[4]) 
                and re.match(r"^[ATGC]$", columns[5])): 
                return True
            else:
                return False

Theres several problems here which I dont know how to solve:

when I print columns[0] I only get the first row of the column and not all of the rows.(which I thought the first part of the code answer)

all the regex part - I tried to run it with a file that should return True but I keep getting False.

Any help is appreciated!

Example of one line in the file:

Output:
['chrX', '74226650', '.', 'T', 'C', '50', '.', 'DP=385;VDB=0;SGB=-0.693147;RPB=0.982669;MQB=1;BQB=0.947576;MQ0F=0;AC=2;AN=2;DP4=0,95,0,289;MQ=20', 'GT:PL:DP', '1/1:78,127,0:384']