CODEWITHSUNDEEP
pythondirectory
Tbevans88
Tbevans88

Reputation: 103

Nested While loop that creates directories with sub directories in Python

I'm trying to write a nested while loop that will create n number of folders with n number of sub-directories. The problem with my current code is that the first folder created does not contain the sub-directories. Only the 2nd directory made contains the sub-directories. My goal is to write a program that runs a parametric sweep with groundwater modeling software, and I need these directories to save the results. 

import subprocess, os

i = 1
j = 1
while i <= 2:
    path = r'C:/Users/TEvans/Desktop/Testing/slope%d' % i 
    if not os.path.exists(path): os.makedirs(path)
    os.chdir(path)
    i = i+1
    while j <= 3:
        path1 = r'C:/Users/TEvans/Desktop/Testing/slope%d/r%d' % (i, j)
        if not os.path.exists(path1): os.makedirs(path1)
        j = j+1

Upvotes: 0

Views: 1315

Answers (4)

Robᵩ
Robᵩ

Reputation: 168616

Some of your code is redundant, and (as others mentioned) the while is confusing your math.

Here is a simpler, nearly equivalent version:

import os
for i in (1,2):
  for j in (1,2,3):
    path1 = r'C:/Users/TEvans/Desktop/Testing/slope%d/r%d' % (i, j)
    if not os.path.exists(path1): os.makedirs(path1)

  • I removed the call to os.makedirs() in the outer loop since those directories will be created by the inner loop's os.makedirs().

  • I fixed the math for both i and j to reflect what I believe you intended.

  • I removed the call to os.chdir() because you are using absolute paths and the call appeared to be otherwise unnecessary.

Upvotes: 2

Jesse
Jesse

Reputation: 317

The problem is with the loop constructs. This should do the trick:

import subprocess, os

for i in range(0,2):
    path = r'C:/Users/TEvans/Desktop/Testing/slope%d' % i 
    if not os.path.exists(path): os.makedirs(path)
    os.chdir(path)
    for j in range(0,3):
        path1 = r'C:/Users/TEvans/Desktop/Testing/slope%d/r%d' % (i, j)
        if not os.path.exists(path1): os.makedirs(path1)

The 'for' construct ensures that the variable is only incremented after the entire code-block has been executed, in stead of somewhere in between, as is the case in your code fragment.

Upvotes: 0

Andrew Clark
Andrew Clark

Reputation: 208435

Your problem is that i has already been incremented before the inner while loop is entered, you could fix this by moving the i = i+1 line so that it is the last thing that is done in the while i <= 2 loop.

However a better solution would be to just use a for loop:

for i in range(1, 3):
    path = r'C:/Users/TEvans/Desktop/Testing/slope%d' % i 
    if not os.path.exists(path): os.makedirs(path)
    os.chdir(path)
    for j in range(1, 4):
        path1 = r'C:/Users/TEvans/Desktop/Testing/slope%d/r%d' % (i, j)
        if not os.path.exists(path1): os.makedirs(path1)

Upvotes: 0

wRAR
wRAR

Reputation: 25693

When os.makedirs(path1) is called for the first time i is already incremented. If you used a foor loop the code would be not only cleaner but more correct.

Upvotes: 1

Related Questions