read a gene sequence in fasta file count number of G and return it

def count_G_in_fasta_file(fasta_file):
    with open(fasta_file) as file:
        count = 0
        for line in file:
            if line[0] == ">":
                continue
            for base in line:
                if base == "G":
                    count += 1
    return count