✨ empty_set_literal - Create an empty set using a literal

Author: DahlitzFlorian

ebook/chapters/standard_lib_chapters/non_categorized.tex

@@ -237,3 +237,22 @@ \subsection{Count Elements Between Thresholds}
 $ python count_thresholds.py
 3
 \end{lstlisting}
+
+
+\subsection{Empty Set Literal}
+
+People, who are new to Python, meeting the built-in set type for the first time often get confused when trying to create an empty set by using the \lstinline|{}| literal.
+This literal is already reserved for creating empty dictionaries.
+The normal way to create a new empty set in Python is to use the \lstinline{set()} constructor.
+However, if you like, you can use a literal, too!
+
+\lstinputlisting[caption=empty\_set\_literal.py]{../standard_lib/empty_set_literal.py}
+
+What happens here is that an empty list (using the list literal \lstinline{[]}) is created and unpacked using the \lstinline{*}-operator.
+The elements from the unpacked empty list are passed to the curly braces.
+Even though no elements at all are passed to the set literal, Python accepts it as valid set creation syntax.
+
+\begin{lstlisting}[caption=Output of empty\_set\_literal.py]
+$ python empty_set_literal.py
+set()
+\end{lstlisting}

ebook/python-snippets.epub

@@ -21,6 +21,7 @@ A collection of useful snippets using only the standard library.
 | dict_based_on_lists | Create a dict based on two lists |
 | disassemble_bytecode | Shows the bytecode representation of f-strings and str() conversion of integers |
 | drawing_turtle | Drawing a dragon symbol using Python's built-in turtle |
+| empty_set_literal | Create an empty set using a literal |
 | emulate_switch_case | Emulate switch-case-statements as they don't exist in Python |
 | file_matching_regex | Find matching files using `re` and `fnmatch` |
 | fill_zeros | Fill strings using leading zeros. |

ebook/python-snippets.mobi

@@ -0,0 +1,2 @@
+empty_set = {*[]}
+print(empty_set)