def test_regard_as(self):
"""
conversion of variable type
"""
df = pd.read_csv(self.test_data)
inspector = Inspector(df, m_cats=20)
self.assertEqual(inspector.result.loc["age", "variable"],
VariableType.continuous.name)
inspector.regard_as_categorical("age")
self.assertEqual(inspector.result.loc["age", "variable"],
VariableType.categorical.name)
## If we set m_cats, then the inspection logic will be executed.
## As a result the manual setting will be lost.
inspector.m_cats = 21
self.assertEqual(inspector.result.loc["age", "variable"],
VariableType.continuous.name)
#
# 1. `constant`: `n_unique==1`.
# 2. `binary`: it can take only two values. `n_unique==2`
# 3. `categorical`: it can take finite number of values. `dtype = "object"` or `n_unique <= m_cats`
# 4. `continuous`: it can take values in real numbers or timestamps.
#
# Remarks:
#
# - We do not care if there is an ordering of values: A nominal variable and an ordinal variable are both just a categorical variable.
# - We regard a binary variable as a special case of a categorical variable.
# - A constant variable is neither categorical nor continuous.
# - The data type `datetime` is always regarded as a continuous variable, even though it can actually be a categorical variable (such as year-month).
#
# If you want to change the result, you can modify `m_cats` or use `regard_as_categorical()` or `regard_as_continuous()`.
inspector.regard_as_categorical("age")
inspector.result.loc["age", :] ## The variable type of age is categorical
# If we assign a number to `m_cats`, then the inspection is computed again. As a result your manual modification of variable types will be lost.
inspector.m_cats = 20
inspector.result.query(
"dtype == 'int64'") ## The variable type of age is now continuous.
# If you want to calculate the inspection once again because you converted a column, then `make_an_inspection()` does the job.
inspector.make_an_inspection()
# We can get easily the list of categorical/continuous variables. (Note that a constant variable is neither categorical nor continuous.)
print(inspector.get_cats()