ValueError: not enough values to unpack (expected 3, got 2)

[nouraIT]

Traceback (most recent call last):
File "draw.py", line 78, in
_, contour_gs, _ = cv2.findContours(thresh.copy(), cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
ValueError: not enough values to unpack (expected 3, got 2)

environment:
Package Version

---

certifi 2020.6.20
chardet 3.0.4
cycler 0.10.0
idna 2.10
joblib 0.17.0
kiwisolver 1.2.0
matplotlib 3.3.2
mkl-fft 1.2.0
mkl-random 1.1.1
mkl-service 2.3.0
numpy 1.19.2
olefile 0.46
opencv-python 4.4.0.44
Pillow 8.0.1
pip 20.2.4
pyparsing 2.4.7
python-dateutil 2.8.1
quickdraw 0.1.0
requests 2.24.0
scikit-learn 0.23.2
scipy 1.5.3
setuptools 50.3.0.post20201006
six 1.15.0
sklearn 0.0
threadpoolctl 2.1.0
torch 1.6.0
torchvision 0.7.0
urllib3 1.25.11
wheel 0.35.1

[deeplearning987]

Hello Team,

I tried to resolve the above error but i'm facing another issue.

removed front underscore _

contours, _ = cv2.findContours(mask.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

Can you help ?