Increment number in string

Question

I am trying to get the following output until a certain condition is met.

test_1.jpg
test_2.jpg
..
test_50.jpg

The solution (if you could remotely call

Answer 1

Update for Python v3.6+ - using formatted string literals:

for n in range(1,51):
    print(f'test_{n}')

Answer 2

It's probably easiest to keep dstPath something like "test_%d.jpg", and just pass it a varying count:

dstPath = "test_%d.jpg"
i = 1
while os.path.exists(dstPath % i):
    i += 1
dstPath = dstPath % i # Final name

Answer 3

Print out the value of parts[0] each time you go round the loop ... I think you may be surprised,

Answer 4

It seems as though your condition os.path.exists(dstPath) is matching the same renamed file multiple times. So for example, it renames test.jpg to test_1.jpg; then renames test_1.jpg to test_1_2.jpg, etc.

Answer 5

for j in range(1,10):
    print("test_{0}.jpg".format(j))

enter image description here