断言两个帧不相等

Question

I need to test that two pandas dataframes are not equal. Is there an equivalent to pandas assert_frame_equal function that does this? If not, what's the best/safest way to assert that the frames aren't equal?

Answer 1

You could write your own assertion function that uses assert_frame_equal() and inverts the result:

def assert_frame_not_equal(*args, **kwargs):
    try:
        assert_frame_equal(*args, **kwargs)
    except AssertionError:
        # frames are not equal
        pass
    else:
        # frames are equal
        raise AssertionError

This will use the same logic that assert_frame_equal() uses for comparing data frames, so the question of what constitutes equality is avoided - inequality is simply the opposite of whatever assert_frame_equal() determines.

Answer 2

Assuming assert_frame_equal behaves like assert (meaning either nothing happens or it raises AssertionError ) then you probably can just wrap it in a try :

def assert_frame_not_equal(df1, df2):
    try:
        assert_frame_equal(df1, df2)
        raise AssertionError('DataFrames are equal.')
    except AssertionError:
        pass

Add *args and/or **kwargs as desired for flexibility.

Answer 3

Yes there is :

# Let us suppose you have two dataframes df1 and df2
# Check for equality by using
df1.equals(df2)

Use not to assert that they are not equal