# Cannot create tracker **URL:** \ **Category:** Python\ **Created:** [January 8, 2021, 1:56pm UTC](https://forum.opencv.org/t/cannot-create-tracker/738 "2021-01-08T13:56:54Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![j.eslava](https://avatars.discourse-cdn.com/v4/letter/j/9de0a6/32.png) [@j.eslava](https://forum.opencv.org/u/j.eslava)\ **Post date:** [January 8, 2021, 1:56pm UTC](https://forum.opencv.org/t/cannot-create-tracker/738/1 "2021-01-08T13:56:54Z")
Hello, I have a working code. I developed it on my Win10 computer then ported it to a Ubuntu machine. Everything works on my computer but I cannot create any of the trackers on the Ubuntu computer. When I execute > tracker = cv2.TrackerBoosting\_create() I see this error message: > Traceback (most recent call last): > File “\”, line 1, in \ > AttributeError: module ‘cv2.cv2’ has no attribute ‘Tracker\_create’ My computer: Win10, Python3.8.5, Opencv4.0.1, Opencv-contrib-python4.4.0.46 Other computer: Ubuntu16.04, Python3.6.9, Opencv-contrib-python 4.5.1.48 I have no idea about why I cannot create the tracker on the Ubuntu machine. ---
**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\ **Post date:** [January 8, 2021, 3:15pm UTC](https://forum.opencv.org/t/cannot-create-tracker/738/2 "2021-01-08T15:15:02Z")
> [@j.eslava](#): > > Opencv4.0.1, Opencv-contrib-python4.4.0.46 how did you install any of that ? if it was via pip, make sure to install **only** opencv-contrib-python (NOT opencv-python) else the latter will “shadow” the former, and you cannot use the contrib extra functionality ---
**Author:** ![j.eslava](https://avatars.discourse-cdn.com/v4/letter/j/9de0a6/32.png) [@j.eslava](https://forum.opencv.org/u/j.eslava)\ **Post date:** [January 8, 2021, 3:35pm UTC](https://forum.opencv.org/t/cannot-create-tracker/738/3 "2021-01-08T15:35:10Z")
I installed them with pip3. I work in a python3 virtual environment. I uninstalled both opencv and opencv contrib and installed again opencv-contrib-python with pip3. now > print(cv2.\__version_\_) shows 4.5.1. But when I run > pip3 show opencv I see this warning: > WARNING: Package(s) not found: opencv I believe there is something wrong with my virtual environment but I see the correct opencv version when I print it in my python script. This confuses me. I have Opencv-contrib-python4.4.0.46 on my windows machine. But I have this problem on the Ubuntu machine. Everything works on the Windows machine. **EDIT:** On my win10 computer I created a new conda environment and installed the latest opencv-contrib-python with pip. I see the same error message when I try to create the tracker in the new environment. There is no problem with opencv-contrib-python ver. 4.4.0.46. ---
**Author:** ![ieliz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/ieliz/32/86_2.png) [@ieliz](https://forum.opencv.org/u/ieliz)\ **Post date:** [January 11, 2021, 8:07am UTC](https://forum.opencv.org/t/cannot-create-tracker/738/4 "2021-01-11T08:07:45Z")
Hi! I think your problems with the latest version of the opencv-contrib-python can be related to changes in tracking API: > **[opencv/opencv\_contrib](https://github.com/opencv/opencv_contrib/compare/37315babf9984a5b6aa981644a20dd8df1a5ff02...b91a781cbc1285d441aa682926d93d8c23678b0b)** > > re/37315babf9984a5b6aa981644a20dd8df1a5ff02...b91a781cbc1285d441aa682926d93d8c23678b0b I tried to use Win10, Python 3.8.5, opencv-contrib-python==4.4.0.46, and all works fine. Please, use the 4.4.0.46 version for now and keep watching for changes in tracking API: > > > Tracking API > Author: Ilya Elizarov > Link: #18481 > Status: Draft > Platforms: All > Complexity: N/A > Introduction and Rationale > The main goal of this proposal is the renewal of the tracking... and changes of opencv-python: > **[skvark/opencv-python](https://github.com/skvark/opencv-python)** > > Automated CI toolchain to produce precompiled opencv-python, opencv-python-headless, opencv-contrib-python and opencv-contrib-python-headless packages. 🙂 Also, the **pip show open-contrib-python** command should work, instead of **pip3 show opencv**. ---
**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\ **Post date:** [January 11, 2021, 10:39am UTC](https://forum.opencv.org/t/cannot-create-tracker/738/5 "2021-01-11T10:39:12Z")
indeed, latest changes to the tracking api seem a bit messy. while ``` TrackerCSRT TrackerGOTURN TrackerKCF TrackerMIL ``` behave as expected (they were moved into the main opencv repo), we now have: ``` legacy_MultiTracker legacy_Tracker legacy_TrackerBoosting legacy_TrackerCSRT legacy_TrackerKCF legacy_TrackerMIL legacy_TrackerMOSSE legacy_TrackerMedianFlow legacy_TrackerTLD ``` (from `>>>help(cv2)`) when using latest 4.5.1, please try: ``` tracker = cv2.legacy.TrackerBoosting_create() ``` ---
**Author:** ![ieliz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/ieliz/32/86_2.png) [@ieliz](https://forum.opencv.org/u/ieliz)\ **Post date:** [January 11, 2021, 10:58am UTC](https://forum.opencv.org/t/cannot-create-tracker/738/6 "2021-01-11T10:58:22Z")
Working for me with Win10, opencv-contrib-python last version and Python 3.8.5.