Plotting histogram of dataframe column

[Mark17]

I have the answer, but I don't understand it:

from matplotlib import pyplot as plt
%matplotlib inline #Jupiter notebook
plt.style.use('seaborn')

# Plot a histogram of combined points
plt.hist(super_bowls.combined_pts)
plt.xlabel('Combined Points')
plt.ylabel('Number of Super Bowls')
plt.show()

# Display the highest- and lowest-scoring Super Bowls
display(super_bowls[super_bowls['combined_pts'] > 70])

Please compare lines 6 and 12. Why does the syntax for plot.hist include a dot between the name of dataframe (super_bowls) and column in that df (combined_pts)?

Line 12, in contrast, uses two brackets to look up (I think) rows in a dataframe for whom the combined_pts column value is greater than 70.

Thanks!

---

I just learned .columns is a component of DataFrames. I can print(super_bowl.combined_pts) to get a 2-column list of row # and combined points.

This helps me understand line 6.

Why does Line 12 require the double brackets, though?

[jefsummers]

The dataframe understands slices. So in English line 12 would be Display super_bowls where super_bowls combined points is greater than 70.

[Mark17]

The dataframe understands slices. So in English line 12 would be Display super_bowls where super_bowls combined points is greater than 70.

Why couldn't I have used a dot there since .columns is a component of DF's?

[jefsummers]

You can.

display(super_bowls[super_bowls.combined_pts > 70])

should work

[Mark17]

You can.

display(super_bowls[super_bowls.combined_pts > 70])

should work

Seriously?? I'm so confused... I'll have to study this.

Thanks Jef!