Python looping problem with mosaiced imagery

Question

I'm trying to get V1 and V2 mosaiced together. However, the first if statement only shows the last image that is being used for the mosaic (V1). The seconded part of the statement is changing the image that is being mosaiced together. I need them both to change and paired with one another in the same loop to have every mosaic be unique from the 2 sided camera array. One side of the camera array starts with 0_000 and the other side starts with 1_000 with the same matching end numbers. The problem is that the first part of the loop is finished before the whole operation is complete because of the seconded loop.

for image in os.listdir(newpath):

     if os.path.isfile(os.path.join(newpath, image))and '0_00' in image:
         V1 = Image.open(newpath + image)
         image2_size = V1.size
     if os.path.isfile(os.path.join(newpath,image)) and '1_' in image:
         V2 = Image.open(newpath + image)
         image1_size = V2.size
         new_image = Image.new('RGB',(2*image1_size[0], image1_size[1]), (250,250,250))
         new_image.paste(V2,(0,100))
         new_image.paste(V1,(image1_size[0],0))
         EXIF = V2.getexif()
         new_image.save(newpath2 + image, format=new_image.format, optimize=True, exif = EXIF)