Python: Miscellaneous

1. Anaconda/Miniconda

1.1) Create new environment

conda create -n py39 python=3.9

1.2) Add kernel to Jupyter

source activate py39
python -m ipykernel install --name py39
source deactivate

1.3) Install mamba

conda install mamba -n base -c conda-forge

1.4) Add existing R installation to Jupyter

• Check R home directory:

    R.home("bin")
  

• In Command Prompt (Windows):

    cd 'C:\Program Files\R\R-4.0.0\bin\x64\'
    conda activate my_env
    R.exe
    install.packages("IRkernel")
    IRkernel::installspec()
    q()
  

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2. Matplotlib

• Import:

    import matplotlib.pyplot as plt
    %matplotlib inline
    plt.rcParams.update({'text.usetex': True, 'figure.dpi':150, 'savefig.dpi':300})
  

• Use subset of colormap:

    cmap = matplotlib.colors.ListedColormap(plt.cm.tab10.colors[:2])
  

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3. Pytables

• Close all opened files:

    tables.file._open_files.close_all()
  

4. Jupyter

• Use full width:

    from IPython.display import display, HTML
    display(HTML("<style>.container { width:100% !important; }</style>"))
  

5. Reload (ref)

%load_ext autoreload
%autoreload 2

6. Warnings (ref)

• Temporary:

    import warnings
  
    def fxn():
        warnings.warn("deprecated", DeprecationWarning)
  
    with warnings.catch_warnings():
        warnings.simplefilter("ignore")
        warnings.filterwarnings("ignore", category=DeprecationWarning)
        fxn()
  

6. HTTP Server (Python 3)

python -m http.server
python -m http.server 8000 --bind 127.0.0.1 --directory /tmp/