how to read the first line in a file python

# attempt #1
f = open("Bills.txt", "w")
f.write("\n".join(map(lambda x: str(x), bill_List)))
f.close()


# attempt #2
# Open a file in write mode
f = open('Bills.txt', 'w')
for item in bill_List:
f.write("%s\n" % item)
# Close opend file
f.close()

# attempt #3

with open('Bills.txt', 'w') as f:
for s in bill_List:
    f.write(s + '\n')

with open('Bills.txt', 'r') as f:
bill_List = [line.rstrip('\n') for line in f]

# attempt #4
with open('Bills.txt', 'w') as out_file:
out_file.write('\n'.join(
    bill_List))