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Graph multiple lines in Python (one line per categorie) in one dataframe

I have a dataframe where I want to create a line graph. I want one line per category and on the x-axis I want the date, and on the y-axis the 12MKG. I don’t know how to put labels on the lines and make the lines different colours per category.

So far I have tried:

plt.plot(df['date'], datatoplot['12MKG'])
date categorie 12MKG
202001 cat1 0.9836956
202002 cat1 0.9836956
202003 cat1 0.9831461
202004 cat1 0.97206706
202005 cat1 0.9698492
202006 cat1 0.97630334
202007 cat1 0.9787234
202008 cat1 0.9810606
202009 cat1 0.9825784
202010 cat1 0.98165137
202011 cat1 0.9768116
202012 cat1 0.96666664
202101 cat1 0.9655172
202102 cat1 0.95214105
202103 cat1 0.93721974
202104 cat1 0.9419087
202105 cat1 0.93158954
202106 cat1 0.9189189
202107 cat1 0.9144603
202001 cat2 0.3118644
202002 cat2 0.3006993
202003 cat2 0.3017544
202004 cat2 0.29433963
202005 cat2 0.3030303
202006 cat2 0.30483273
202007 cat2 0.33206108
202008 cat2 0.33730158
202009 cat2 0.344
202010 cat2 0.34008098
202011 cat2 0.34051725
202012 cat2 0.3224299
202101 cat2 0.33027524
202102 cat2 0.3187773
202103 cat2 0.29338843
202104 cat2 0.28458497
202105 cat2 0.2804878
202106 cat2 0.2804878
202107 cat2 0.2631579
Solution

  • You can use colormap to get different colors for each line and df.loc to filter each category

    import matplotlib.pylab as pl
import matplotlib.pyplot as plt

labels = set(df['categorie'].values)
colors = pl.cm.jet(np.linspace(0,1,len(labels)))
for key, color in zip(labels, range(len(labels))):
    data_x = df.loc[df['categorie']==key]['date']
    data_y = df.loc[df['categorie']==key]['12MKG']
    plt.plot(data_x, data_y, color=colors[color], label=key)
plt.legend()
plt.show()

    See here for more details on colormaps