External-Sort

About the code : This folder has 2 files -- 1. lfile.py - to generate a text file with random numbers 2. problem3.py - Python file to have implementation of external sort

How to run the code.

1. From the linux terminal go to the directory where code is present

2. Create a "largefile.txt" using the lfile.py module by typing

    python lfile.py
   

3. If one wishes to sort multiple files then run the above command multiple times by changing the output file name in lfile.py. It will create multiple files with random numbers in it. You can also vary the file sizes by changing the number of iteration in the for loop. Copy all the files to a input directory (say Input).

4. Type "python" (without quotes)

5. Suppose the input directory name in "Input" and you want to produce a sorted file by name "output.txt"

6. Type the following lines in the terminal

    import problem3 as pr
    ob = pr.sort('Input','out.txt')
    ob.external_sort()
   

7. Process 6. will take some time to sort the files in the given input directory.

8. To rotate a sorted list type

    ob.rotate()
   

   Follow the steps asked by the function. The output response will be in a text file "rotate.txt" in the same folder where the problem3.py is present

9. To get the minimum element in the sorted rotated file type the command

    ob.find_min()
   

Sample Run

anurag@Anurag:~/Desktop/Problem2$ python

>>> import problem3 as pr
>>> ob = pr.sort('Input','out.txt')
>>> ob.external_sort()
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Merging chunks, Please wait till the processing ends!!!
Performing Essential cleanups !!!
>>> ob.rotate()
Enter the value of N
20000
Enter the number of times you want to perform rotation
Hit enter if you want perform random number of rotations

>>> ob.find_min()
Minimum number in rotated list is: 10