update error related contents

Author: zmx721

modules/module1/slides/module1_29.qmd

@@ -77,27 +77,19 @@ Now we can use `.value_counts()` on this `mfr_column` variable to reference it,
 ---
 
 ```{python}
-mfr_col_wrong = cereal[['mfr']]
-mfr_col_wrong
+mfr_col_dataframe = cereal[['mfr']]
+mfr_col_dataframe
 ```
 
 <br>
 
-```python
-mfr_col_wrong.value_counts()
+```{python}
+mfr_col_dataframe.value_counts()
 ```
 
-```out
-AttributeError: 'DataFrame' object has no attribute 'value_counts'
-
-Detailed traceback: 
-  File "<string>", line 1, in <module>
-  File "/usr/local/lib/python3.7/site-packages/pandas/core/generic.py", line 5274, in __getattr__
-    return object.__getattribute__(self, name)
-```
 
 :::{.notes} 
-If we did instead use double square brackets with `pd.value_counts()`, we would get an error. So it is important to take care and remember when you are using `value_counts()`, you only use one set of square brackets.
+`value_counts()` can also be called on a DataFrame to count unique rows.
 :::
 
 ---

modules/module2/slides/module2_20.qmd

@@ -195,20 +195,16 @@ cereal[cereal['mfr'] == 'Q', 'mfr'] = 'Quaker'
 ```
 
 ```out
-TypeError: 'Series' objects are mutable, thus they cannot be hashed
+TypeError: unhashable type: 'Series'
 
 Detailed traceback: 
   File "<string>", line 1, in <module>
-  File "/usr/local/lib/python3.7/site-packages/pandas/core/frame.py", line 2938, in __setitem__
+  File "/usr/local/lib/python3.12/site-packages/pandas/core/frame.py", line 4311, in __setitem__
     self._set_item(key, value)
-  File "/usr/local/lib/python3.7/site-packages/pandas/core/frame.py", line 3000, in _set_item
-    value = self._sanitize_column(key, value)
-  File "/usr/local/lib/python3.7/site-packages/pandas/core/frame.py", line 3666, in _sanitize_column
-    if broadcast and key in self.columns and value.ndim == 1:
-  File "/usr/local/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 3899, in __contains__
+  File "/usr/local/lib/python3.12/site-packages/pandas/core/frame.py", line 4527, in _set_item
+    key in self.columns
+  File "/usr/local/lib/python3.12/site-packages/pandas/core/indexes/base.py", line 5358, in __contains__
     hash(key)
-  File "/usr/local/lib/python3.7/site-packages/pandas/core/generic.py", line 1799, in __hash__
-    f"{repr(type(self).__name__)} objects are mutable, "
 ```