I’m curious to find the difference between assert_frame_equal
and equal
.
Both are for checking the equality of two data. It applies for assert_series_equal
and assert_index_equal
. So what is the difference between equals and testing functions?
So far I found was testing functions gives little more flexibility to compare the values, like check_dtpye
options etc., and differs from returning values Is this the only difference between them?
or otherwise, When Should I use testing functions other than equals method?
df1=pd.DataFrame({'a':[1,2,3,4,5],'b':[6,7,8,9,10]}) df2=pd.DataFrame({'a':[1,2,3,4,5],'b':[6,7,8,9,10]}) pd.testing.assert_frame_equal(df1,df2) print df1.equals(df2) pd.testing.assert_series_equal(df1['a'],df2['a']) print df1['a'].equals(df2['a']) pd.testing.assert_index_equal(df1.index,df2.index) print df1.index.equals(df2.index)
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Answer
assert_frame_equal
throws an AssertionError
when two DataFrames aren’t equal.
pd.testing.assert_frame_equal(df1, df2) # no result - pass pd.testing.assert_frame_equal(df1, pd.DataFrame()) # throws error - fail # AssertionError
DataFrame.equals
simply returns a boolean True/False.
df1.equals(df2) # True df1.equals(pd.DataFrame()) # False
This is also the case for the other functions defined in pd.testing
, which are used to develop unit tests for pandas code.