Draw a plot in which the Y-axis text data (not numeric), and X-axis numeric data

Question

I can create a simple columnar diagram in a matplotlib according to the \'simple\' dictionary:

import matplotlib.pyplot as plt
D = {u\'Label1\':26, u\'Label2\'         


        

Answer 1

You may use numpy to convert the dictionary to an array with two columns, which can be plotted.

import matplotlib.pyplot as plt
import numpy as np

T_OLD = {'10' : 'need1', '11':'need2', '12':'need1', '13':'need2','14':'need1'}
x = list(zip(*T_OLD.items()))
# sort array, since dictionary is unsorted
x = np.array(x)[:,np.argsort(x[0])].T
# let second column be "True" if "need2", else be "False
x[:,1] = (x[:,1] == "need2").astype(int)

# plot the two columns of the array
plt.plot(x[:,0], x[:,1])
#set the labels accordinly
plt.gca().set_yticks([0,1])
plt.gca().set_yticklabels(['need1', 'need2'])

plt.show()

The following would be a version, which is independent on the actual content of the dictionary; only assumption is that the keys can be converted to floats.

import matplotlib.pyplot as plt
import numpy as np

T_OLD = {'10': 'run', '11': 'tea', '12': 'mathematics', '13': 'run', '14' :'chemistry'}
x = np.array(list(zip(*T_OLD.items())))
u, ind = np.unique(x[1,:], return_inverse=True)
x[1,:] = ind
x = x.astype(float)[:,np.argsort(x[0])].T

# plot the two columns of the array
plt.plot(x[:,0], x[:,1])
#set the labels accordinly
plt.gca().set_yticks(range(len(u)))
plt.gca().set_yticklabels(u)

plt.show()