Nested loop and File io

Question

I am making a simple program for fun. This should take input for X amount of files to be filled with Y amount of random 0's and 1's.

When I run this I would like to have 2 files both filled with 20 random 0's and 1's in each file. At the moment when I run this only the first file gets filled and the second one is left empty.

I think it has something to do with my second loop but I am not sure, how can I get this to work?

import random

fileamount = int(raw_input("How many files should I make? > "))
amount = int(raw_input("How many characters in the files? > "))
print "I will now make %r files with %r characters in them!\n" % (fileamount, amount)
s1 = 0
s2 = 0

while s2 < fileamount:
    s2 = s2 + 1
    textfile = file('a'+str(s2), 'wt')
    while s1 < amount:
        s1 = s1 + 1
        textfile.write(str(random.randint(0,1)))

unutbu · Accepted Answer · 2013-07-25 22:14:51Z

3

In addition to reseting the value of s1, make sure you close your files. Sometimes, the output does not get written to the file if the program ends before the buffer is written to disk.

You can guarantee the file is closed by using a with statement. The file will be closed when Python's flow of execution leaves the with suite.

import random

fileamount = int(raw_input("How many files should I make? > "))
amount = int(raw_input("How many characters in the files? > "))
print "I will now make %r files with %r characters in them!\n" % (fileamount, amount)

for s2 in range(fileamount):
    with open('a'+str(s2), 'wt') as textfile:
        for s1 in range(amount):
            textfile.write(str(random.randint(0,1)))

answered Jul 25, 2013 at 22:14

unutbu

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Comments

zhangyangyu · Accepted Answer · 2013-07-25 22:12:46Z

0

You don't reinit s1 to 0. So the second time there will be nothing written to the file.

import random

fileamount = int(raw_input("How many files should I make? > "))
amount = int(raw_input("How many characters in the files? > "))
print "I will now make %r files with %r characters in them!\n" % (fileamount, amount)

s2 = 0
while s2 < fileamount:
    s2 = s2 + 1
    textfile = open('a'+str(s2), 'wt') #use open
    s1 = 0
    while s1 < amount:
        s1 = s1 + 1
        textfile.write(str(random.randint(0,1)))
    textfile.close() #don't forget to close

answered Jul 25, 2013 at 22:12

zhangyangyu

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Comments

rnbguy · Accepted Answer · 2013-07-25 22:20:26Z

0

s2 does not go back to zero after first loop. So next file does not get any character. So put s2=0 just before the inner loop.

better to use range function.

import random

fileamount = int(raw_input("How many files should I make? > "))
amount = int(raw_input("How many characters in the files? > "))
print "I will now make %r files with %r characters in them!\n" % (fileamount, amount)

for s2 in range(fileamount):
    textfile = file('a'+str(s2+1), 'wt')
    for b in range(amount):
        textfile.write(str(random.randint(0,1)))

answered Jul 25, 2013 at 22:20

rnbguy

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