Melting with not present column does not produce error

doc/source/whatsnew/v0.24.0.txt

@@ -1344,6 +1344,7 @@ Reshaping
 - Bug in :func:`pandas.concat` when concatenating a multicolumn DataFrame with tz-aware data against a DataFrame with a different number of columns (:issue`22796`)
 - Bug in :func:`merge_asof` where confusing error message raised when attempting to merge with missing values (:issue:`23189`)
 - Bug in :meth:`DataFrame.nsmallest` and :meth:`DataFrame.nlargest` for dataframes that have :class:`MultiIndex`ed columns (:issue:`23033`).
+- Bug in :func: `pandas.melt` when passing column names that do no exist in dataframe (:issue:`23575`)
 
 .. _whatsnew_0240.bug_fixes.sparse:
 

pandas/core/reshape/melt.py

@@ -12,6 +12,7 @@
 
 from pandas import compat
 from pandas.core.arrays import Categorical
+from pandas.core.indexes.base import Index
 from pandas.core.frame import _shared_docs
 from pandas.core.reshape.concat import concat
 from pandas.core.tools.numeric import to_numeric
@@ -32,7 +33,12 @@ def melt(frame, id_vars=None, value_vars=None, var_name=None,
             raise ValueError('id_vars must be a list of tuples when columns'
                              ' are a MultiIndex')
         else:
+            # Check that `id_vars` are in frame
             id_vars = list(id_vars)
+            missing = Index(id_vars).difference(frame.columns)
+            if not missing.empty:
+                raise ValueError('Columns {missing} are not in'
+                                 ' dataframe'.format(missing=missing))
     else:
         id_vars = []
 
@@ -45,6 +51,11 @@ def melt(frame, id_vars=None, value_vars=None, var_name=None,
                              ' columns are a MultiIndex')
         else:
             value_vars = list(value_vars)
+            # Check that `value_vars` are in frame
+            missing = Index(value_vars).difference(frame.columns)
+            if not missing.empty:
+                raise ValueError('Columns {missing} are not in'
+                                 ' dataframe'.format(missing=missing))
         frame = frame.loc[:, id_vars + value_vars]
     else:
         frame = frame.copy()

pandas/tests/reshape/test_melt.py

@@ -661,3 +661,20 @@ def test_col_substring_of_stubname(self):
                                  i=['node_id', 'A'],
                                  j='time')
         tm.assert_frame_equal(result, expected)
+
+    def test_melt_missing_columns(self):
+        # Addresses issue #23575
+        # This test is to ensure that pandas raises an error if melting is
+        # attempted with column names absent from the dataframe
+
+        # Generate data
+        people = ['Susie', 'Alejandro']
+        day = ['Monday', 'Tuesday', 'Wednesday']
+        cols = ['burgers', 'fries']
+        data = [[person, d] + list(np.random.randint(0, 5, len(cols)))
+                for person in people for d in day]
+        df = pd.DataFrame(data, columns=['Name', 'day', 'burgers', 'fries'])
+
+        # Try to melt with missing column name
+        with pytest.raises(ValueError):
+            df.melt(['Name', 'day'], ['Burgers', 'fries'])