Computing GCs | Python Fiddle

import os
BASE_PATH = os.path.join(os.path.expanduser("~"), r'Documents\Python projects\Rosalind')

class Fasta_record:
    def __init__(self, label):
        self.label = label
        self.data = ""
        self.GC = 0

def __str__(self):
        return self.label + '/' + self.data

def get_label(self):
        return self.label
    
    def add_data(self, new_data):
        self.data += new_data
        
    def get_data(self):
        return self.data
   
    def get_GC(self):
        return 100 * float(self.data.count('C') + self.data.count('G')) / len(self.data)
        
data_file=[]
record = Fasta_record("")
max_GC = max_index = 0

data = ('>Rosalind_6404','CCTGCGGAAGATCGGCACTAGAATAGCCAGAACCGTTTCTCTGAGGCTTCCGGCCTTCCC','TCCCACTAATAATTCTGAGG','>Rosalind_5959','CCATCGGTAGCGCATCCTTAGTCCAATTAAGTCCCTATCCAGGCGCTCCGCCGAAGGTCT','ATATCCATTTGTCAGCAGACACGC','>Rosalind_0808','CCACCCTCGTGGTATGGCTAGGCATTCAGGAACCGGAGAACGCTTCAGACCAGCCCGGAC','TGGGAACCTGCGGGCAGTAGGTGGAAT')
##data = open(os.path.join(BASE_PATH,'rosalind_gc.txt'), 'r')

#store data
for line in data:
    line = line.strip()
    if line[0] == '>':
        if record.get_label():
            data_file.append(record) #store old record
        record = Fasta_record(line[1:]) #new record
    else:
        record.add_data(line)
data_file.append(record) #store last record
##data.close()

#compare GCs
for i,record in enumerate(data_file):
    if record.get_GC() > max_GC:
        max_GC = record.get_GC()
        max_index = i

print(data_file[max_index].get_label())
print(max_GC)

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