Making a bill in Python 3 code example

Example 1: how to make a bill in python

tprice = 0
tup = [['apple', '100', '2'], ['blackberry', '100', '23']]
myformat = "{:<10}{:<25}{:<5}{}"

f = open(filename, 'w')
g = open('recpt.txt', 'r')
lines = g.readlines()

for line in lines:
    base = line.split()
    tup.append(base)

print(myformat.format('S.no', 'Product', 'Unit', 'Price'))

for i in range(len(tup)):
    if len(tup[i][0]) <= 7:
        print(myformat.format(str([i + 1]), tup[i][0], tup[i][2], tup[i][1]))
    else:
        print(myformat.format(str([i + 1]), tup[i][0], tup[i][2], tup[i][1]))

    price = int(tup[i][1])
    tprice += price

print(tprice)

Example 2: how to make a bill in python

tprice = 0
tup = [['apple','100','2'],['blackberry','100','23']]
f= open(filename,'w')
g= open('recpt.txt','r')
lines = g.readlines()
for line in lines:
    base = line.split()
    tup.append(base)
print('S.no','\t','Product','\t','Unit','\t','Price')
for i in range(len(tup)):
    if len(tup[i][0]) <= 7:
      print([i+1],'\t',tup[i][0],'\t','\t',tup[i][2],'\t',tup[i][1])
    else:
        print([i+1], '\t', tup[i][0], '\t', tup[i][2],'\t',tup[i][1])
    price = int(tup[i][1])
    tprice += price
print(tprice)

Example 3: python bill

tprice = 0
tup = [['apple','100','2'],['blackberry','100','23']]
f= open(filename,'w')
g= open('recpt.txt','r')
lines = g.readlines()
for line in lines:
    base = line.split()
    tup.append(base)
print('S.no','\t','Product','\t','Unit','\t','Price')
for i in range(len(tup)):
    if len(tup[i][0]) <= 7:
      print([i+1],'\t',tup[i][0],'\t','\t',tup[i][2],'\t',tup[i][1])
    else:
        print([i+1], '\t', tup[i][0], '\t', tup[i][2],'\t',tup[i][1])
    price = int(tup[i][1])
    tprice += price
print(tprice)