python use argparse for passing optional arguments for plotting

Question

I would like to pass optional arguments to a matplotlib script running from the command line.

I have the following:

import numpy as np
import matplotlib.pyplot as plt
import matplotlib
matplotlib.use('Agg')

import pandas as pd
import argparse

parser = argparse.ArgumentParser(description="Plot x,y data in python")
parser.add_argument('-xF',"--x", type=str, metavar='', required=True, help="x-Data")
parser.add_argument('-yF', "--y", type=str, metavar='', required=True, help="y-Data")
parser.add_argument('-o', "--options", nargs="+", default=[], help="Options for plotting")
args = parser.parse_args()

def plot(x, y, xlabel, ylabel, name, legend=None, otherArgs=None):

    xData = pd.read_csv(x) 
    yData = pd.read_csv(y)     

    plt.figure()
    plt.plot(xData, yData, label=legend, *(otherArgs), zorder=1)   
    plt.tight_layout()
    plt.savefig("tst.tiff")

if __name__ == '__main__':
    plot(args.x, args.y, args.options)

However, currently I am not able to do so. Is there any way to pass under the optional arguments other parameters to the plot functions? Set colors, markers, etc.. ?

Best Regards

Asked By: mysticSnake

||

Source

Answer 1

If you will run as

-o color=red marker=o

then you will get list

["color=red", "marker=o"]

and you can use split("=") and dict()

args.options = dict(x.split('=') for x in args.options)

to get it as dictionary

{"color":"red", "marker":"o"}

And then you can use ** to put dictionary

plt.plot(..., **otherArgs)

and it will accept it as correct parameters.

Minimal working code:

For test I put argumenst directly in sys.argv – so I can run it without writing parameters in console.

import numpy as np
import matplotlib.pyplot as plt
import matplotlib
#matplotlib.use('Agg')

import pandas as pd
import argparse

# --- functions ---

def plot(x, y, xlabel='X', ylabel='Y', name='Name', legend=None, otherArgs=None):

    xData = [1,2,3]
    yData = [3,1,1]

    plt.figure()
    plt.plot(xData, yData, label=legend, **otherArgs, zorder=1)   
    plt.tight_layout()
    #plt.savefig("tst.tiff")
    plt.show()

# --- main ---

if __name__ == '__main__':
    
    import sys
    sys.argv += ['--x', '1', '--y', '2', '-o', 'color=red', 'marker=o']

    parser = argparse.ArgumentParser(description="Plot x,y data in python")
    parser.add_argument('-xF',"--x", type=str, metavar='', required=True, help="x-Data")
    parser.add_argument('-yF', "--y", type=str, metavar='', required=True, help="y-Data")
    parser.add_argument('-o', "--options", nargs="+", default=[], help="Options for plotting")
    args = parser.parse_args()

    print('[args.options] before:', args.options)
    
    args.options = dict(x.split('=') for x in args.options)

    print('[args.options] after :', args.options)
    
    plot(args.x, args.y, otherArgs=args.options)

Console:

[args.options] before: ['color=green', 'marker=o']
[args.options] after : {'color': 'green', 'marker': 'o'}

Answered By: furas

python use argparse for passing optional arguments for plotting

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