Update python_packages_required.md

python_packages_required.md

 # Python packages to install:
-* **numpy:** array computing
-* **os:** move files
-* **opencv-python:** (cv2) image processing
-* **matplotlib.pyplot:** plot figures
-* **sklearn:** data mining and data analysis
-* **skimage:**  image processing and computer vision.
 * **argparse:** makes it easy to write user-friendly command-line interfaces 
-* **tensorflow:** open source machine learning library for research and production
-* **keras:** makes it easy to build Convolutional Neural Network
 * **csv:** csv files treatment
+* **keras:** makes it easy to build Convolutional Neural Network
+* **lightgbm:** type of regression model
 * **matlab.engine:** execute Matlab code. It is not easy to install. Follow 
 [this link](https://www.scivision.dev/matlab-engine-callable-from-python-how-to-install-and-setup/). 
 Pay attention if your computer is 32 or 64 bits and follow the path where the 
 package is installed. You have to check the path where *Python* is looking for the packages installed.
-* **subprocess:** execute command line code
-* **re:** regular expression.
-* **time:** time measurement
+* **matplotlib.pyplot:** plot figures. Problem to install it in GPU
+* **numpy:** array computing
+* **opencv-python:** (cv2) image processing
+* **os:** move files
 * **pandas:** dataframe treatment
+* **re:** regular expression.
 * **shutil:** create and delete directories
-* **xgboost:** type of model
-* **lightgbm:** type of model
+* **sklearn:** data mining and data analysis
+* **skimage:**  image processing and computer vision.
 * **statsmodels.api:** create a summary for models
+* **subprocess:** execute command line code
+* **tensorflow:** open source machine learning library for research and production
+* **time:** time measurement
+* **xgboost:** type of regression model
 * **\_\_future\_\_**