Python program Airnef stuck while downloading images

I am using Airnef to download pictures from my Canon DSLR camera through python.

I can download one picture without problems so the whole setup seems to work. However, as soon as I want to download another image the software hangs. The code to me looks quite complex.

Two months ago I did post a thread on TestCams.com. Since I haven't gotten a response, I post this as a python-related question here.

The thread

I start airnef from the command line.

python airnefcmd.py --ipaddress 192.168.188.84 --action getfiles --realtimedownload only --downloadexec open @pf@ --transferorder newestfirst --outputdir "/Users/besi/Desktop"

I connect the camera and I’m shown some information about my connection:

Connection established to 192.168.188.84:15740
Camera Model “Canon EOS 200D”, S/N “XXXXXXXXX”

Now airnef tells me:

Waiting for realtime photos from camera to download.
Press to exit |

I take a picture and it downloads it as expected:

Downloading “IMG_0084.JPG”: 96%

Airnef then shows some more information about this image:

/Users/besi/Desktop/IMG_0084.JPG [size = 4,602,357] in 1.94 seconds (2.26 MB/s)

I take some more pictures but they’re not downloaded and the software is stuck at the prompt:

Waiting for realtime photos from camera to download. Press to exit \

Source code

The source code is available at the Airnef Website. I created a github repository for tackling this issue: https://github.com/besi/airnef

The place where the code is stuck is at airnefcmd.py:3203

from Python program Airnef stuck while downloading images