# [Tutor] Recognizing real numbers

Michael Lewis mjolewis at gmail.com
Wed Feb 22 04:00:40 CET 2012

```Hi everyone,

I have some code where I import a file to use a module. That module that I
import takes text and a multiplier, checks for any numbers in that text and
will then multiply those numbers by the given multiplier. The imported
module is below. I am getting the text from a file that I have which starts
out as:

.5 lb. butter
1.75 Cups Graham Cracker Crumbs
2.0 Cups Powder Sugar
1.0 Cups Peanut Butter
2.0 Cups Semi-sweet Chocolate Chips

It seems that the .isdigit() function that I use doesn't recognize the .5
as a number and therefore doesn't multiply it. How can I get my code to
recognize numbers such as .5, 1.75 as numbers?

Imported module:

def MultiplyText(text, multiplier):
'''Recieve a S & int. For digits in S, multiply by multiplier and
return updated S.'''
return ' '.join(str(float(num) * multiplier) if num.isdigit() else num
for num in text)

Module doing the importing/opening/reading/creating a new file

import Homework5_1 as multiply

def DoubleDigits(file_name):
'''Open file/read file/write new file that doubles all int's in the
read file'''
try:
read_file = open(file_name)
except IOError:
return 'No such file.'
new_file_name = file_name + '2'
try:
write_file = open(new_file_name, 'w')
except IOError:
read_file.close()
return 'No such file to write to.'
for line in read_file:
new_line = line.split()
new_line = ''.join(multiply.MultiplyText(new_line, 2))
write_file.write(new_line + '\n')
read_file.close()
write_file.close()

def main():
DoubleDigits(raw_input('What file do you want to open? '))

if '__name__' == '__main__':
print main()

Output that is written to my file:

Peanut Butter Bars

Ingredients

.5 lb. butter
1.75 Cups Graham Cracker Crumbs
4.0 Cups Powder Sugar
2.0 Cups Peanut Butter
4.0 Cups Semi-sweet Chocolate Chips

Melt butter. Add graham cracker crumbs,
peanut butter and sugar. Mix well and
pat into sheet pan. Cover with melted
chocolate. Refrigerate until semi-firm,
then cut into squares.

--
Michael J. Lewis
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