[BUG] Use __eq__ and .equals() to distinguish between elementwise and whole-object comparison

[genedan]

Are you on the latest chainladder version?

• Yes, this bug occurs on the latest version.

Describe the bug in words

Consider the following example:

import pandas as pd

df1 = pd.DataFrame({'a': [1, 2], 'b': [4, 5]})
df2 = pd.DataFrame({'a': [1, 3], 'b': [7, 5]})

df1 == df2

       a      b
0   True  False
1  False   True

df1.equals(df2)

True

The == operator does elementwise comparison, returning an array of bools. The .equals method compares the whole object, returning a boolean scalar.

How can the bug be reproduced?

Chainladder does not have elementwise comparison, and the == acts as whole-object comparison

import chainladder as cl

raa = cl.load_sample('raa')

raa == raa

True

raa.equals(raa)

Traceback (most recent call last):
    ~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<ipython-input-36-a11e75dbc397>", line 1, in <module>
    raa.equals(raa)
    ^^^^^^^^^^
AttributeError: 'Triangle' object has no attribute 'equals'

What is the expected behavior?

== should do elementwise comparison. The .equals() method should be defined to do whole-object comparison, replacing the current functionality of ==.

Would you be willing to contribute this ticket?

• Yes, absolutely!
• Yes, but I would like some help.
• No.