I presume what you want to do is extract the sequence encapsulated by your primers?

Here's a little function that'll help.

You'll need the re and random modules for this.

#Function definition.

def ext_primer_seq(seq, fwd, rev):

    regstr = r"(?<=" + fwd + r")" + r"[ATGCN\.\*]*" + r"(?=" + rev + r")"
    myregex = re.compile(regstr)

    return(myregex.findall(seq))


#Example run.
fwd = "GTACC"
rev = "CAGGG"

seq = ''.join(random.choices(['A', 'T', 'G', 'C'], k = 50)) + fwd + ''.join(random.choices(['A', 'T', 'G', 'C'], k = 10)) + rev + ''.join(random.choices(['A', 'T', 'G', 'C'], k = 25))

print(seq)

#'GAGTAGCAAGCCACGCGCGTTCTCGACCATCCATAACAAAGCCAAGACGGGTACCCGATACTTTTCAGGGCAGCAAAAGCACGTATCCGCCGGGC'

ext_primer_seq(seq, fwd, rev)
#['CGATACTTTT']

Does this help?