pandas.testing.assert_frame_equal

pandas.testing.assert_frame_equal(left, right, check_dtype=True, check_index_type='equiv', check_column_type='equiv', check_frame_type=True, check_less_precise=_NoDefault.no_default, check_names=True, by_blocks=False, check_exact=False, check_datetimelike_compat=False, check_categorical=True, check_like=False, check_freq=True, check_flags=True, rtol=1e-05, atol=1e-08, obj='DataFrame')

Check that left and right DataFrame are equal.

This function is intended to compare two DataFrames and output any differences. It is mostly intended for use in unit tests. Additional parameters allow varying the strictness of the equality checks performed.

Parameters

leftDataFrame

First DataFrame to compare.

rightDataFrame

Second DataFrame to compare.

check_dtypebool, default True

Whether to check the DataFrame dtype is identical.

check_index_typebool or {‘equiv’}, default ‘equiv’

Whether to check the Index class, dtype and inferred_type are identical.

check_column_typebool or {‘equiv’}, default ‘equiv’

Whether to check the columns class, dtype and inferred_type are identical. Is passed as the exact argument of assert_index_equal().

check_frame_typebool, default True

Whether to check the DataFrame class is identical.

check_less_precisebool or int, default False

Specify comparison precision. Only used when check_exact is False. 5 digits (False) or 3 digits (True) after decimal points are compared. If int, then specify the digits to compare.

When comparing two numbers, if the first number has magnitude less than 1e-5, we compare the two numbers directly and check whether they are equivalent within the specified precision. Otherwise, we compare the ratio of the second number to the first number and check whether it is equivalent to 1 within the specified precision.

Deprecated since version 1.1.0: Use rtol and atol instead to define relative/absolute tolerance, respectively. Similar to math.isclose().

check_namesbool, default True

Whether to check that the names attribute for both the index and column attributes of the DataFrame is identical.

by_blocksbool, default False

Specify how to compare internal data. If False, compare by columns. If True, compare by blocks.

check_exactbool, default False

Whether to compare number exactly.

check_datetimelike_compatbool, default False

Compare datetime-like which is comparable ignoring dtype.

check_categoricalbool, default True

Whether to compare internal Categorical exactly.

check_likebool, default False

If True, ignore the order of index & columns. Note: index labels must match their respective rows (same as in columns) - same labels must be with the same data.

check_freqbool, default True

Whether to check the freq attribute on a DatetimeIndex or TimedeltaIndex.

New in version 1.1.0.

check_flagsbool, default True

Whether to check the flags attribute.

rtolfloat, default 1e-5

Relative tolerance. Only used when check_exact is False.

New in version 1.1.0.

atolfloat, default 1e-8

Absolute tolerance. Only used when check_exact is False.

New in version 1.1.0.

objstr, default ‘DataFrame’

Specify object name being compared, internally used to show appropriate assertion message.

See also

assert_series_equal

Equivalent method for asserting Series equality.

DataFrame.equals

Check DataFrame equality.

Examples

This example shows comparing two DataFrames that are equal but with columns of differing dtypes.

>>> from pandas.testing import assert_frame_equal
>>> df1 = pd.DataFrame({'a': [1, 2], 'b': [3, 4]})
>>> df2 = pd.DataFrame({'a': [1, 2], 'b': [3.0, 4.0]})

df1 equals itself.

>>> assert_frame_equal(df1, df1)

df1 differs from df2 as column ‘b’ is of a different type.

>>> assert_frame_equal(df1, df2)
Traceback (most recent call last):
...
AssertionError: Attributes of DataFrame.iloc[:, 1] (column name="b") are different

Attribute “dtype” are different [left]: int64 [right]: float64

Ignore differing dtypes in columns with check_dtype.

>>> assert_frame_equal(df1, df2, check_dtype=False)