python - Plotting by ignoring missing data in matplotlib

Question

I have been trying to make a program that plots the frequency of usage of a word during Whatsapp chats between 2 people. The word night for example has been used a couple of times on a few days, and 0 times on the most of the days. The graph I have is as follows

Here is the code

word_occurances = [0 for i in range(len(just_dates))]

for i in range(len(just_dates)):
    for j in range(len(df_word)):
        if just_dates[i].date() == word_date[j].date():
            word_occurances[i] += 1

title = person2.rstrip(':') + ' with ' + person1.rstrip(':') + ' usage of the word - ' + word

plt.plot(just_dates, word_occurances, color = 'purple')
plt.gcf().autofmt_xdate()
plt.xlabel('Time')
plt.ylabel('number of times used')
plt.title(title)
plt.savefig('Graphs/Words/' + title + '.jpg', dpi = 200)
plt.show()

word_occurances is a list

[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 2, 0, 0, 0, 1, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

What I want is for the graph to only connect the points where it has been used while showing the entire timeline on the x axis. I don't want the graph to touch 0. How can I do this? I have searched and found similar answers but none have worked the way I them.

Answer 1

You simply have to find the indices of word_occurances on which the corresponding value is greater than zero. With this you can index just_dates to get the corresponding dates.

word_counts = []    # Only word counts > 0
dates = []          # Date of > 0 word count
for i, val in enumerate(word_occurances):
    if val > 0:
        word_counts.append(val)
        dates.append(just_dates[i])

You may want to plot with an underlying bar plot in order to maintain the original scale.

plt.bar(just_dates, word_occurances)
plt.plot(dates, word_counts, 'r--')