There are several ways to insert code into a LaTeX document. One common method is to use the lstlisting environment from the listings package. The package provides options for formatting the code, such as language, font size, and background color. An example of how to use lstlisting to insert a piece of Python code is as follows:

\usepackage{listings}

% ...

\begin{lstlisting}[language=Python]
def hello_world():
    print("Hello, World!")
\end{lstlisting}

Another way is to use verbatim environment.

\begin{verbatim}
def hello_world():
    print("Hello, World!")
\end{verbatim}

Please note that verbatim does not format the code. You can also use other packages like minted, fancyvrb, listingsutf8 to insert code in LaTeX document.

How to use the minted package

The minted package is a LaTeX package that provides syntax highlighting for source code listings using the Pygments library. In order to use the package, you will need to have Pygments installed on your system.

To use the minted package in your LaTeX document, you will need to add the following lines to your preamble:

\usepackage{minted}

Then, you can use the minted environment to insert code listings in your document. The basic syntax is as follows:

\begin{minted}{language}
    [options]
    code
\end{minted}

Where language is the language of the code you are listing (e.g. Python, C++, Java), and options are any additional options you want to pass to the package.

For example, the following code will insert a listing of Python code with the default options:

\begin{minted}{python}
def hello_world():
    print("Hello, World!")
\end{minted}

You can also include options such as fontsize, linenos (line numbers), etc.

\begin{minted}[linenos, fontsize=\footnotesize,numbersep=5pt, frame=lines, framesep=2mm]{python}
def hello_world():
    print("Hello, World!")
\end{minted}

You also need to run a shell command to create a file with highlighted code.

pdflatex --shell-escape file.tex

Please note that minted package requires the use of an external program pygmentize to create the highlighted code, which is why it requires the --shell-escape option when running pdflatex.

How to use the fancyvrb package

The fancyvrb package is a LaTeX package that provides advanced verbatim capabilities, including support for typesetting source code listings with custom fonts and formatting.

To use the fancyvrb package in your LaTeX document, you will need to add the following lines to your preamble:

\usepackage{fancyvrb}

Then, you can use the Verbatim environment to insert code listings in your document. The basic syntax is as follows:

\begin{Verbatim}[options]
    code
\end{Verbatim}

Where options are any additional options you want to pass to the package.

For example, the following code will insert a listing of Python code with the default options:

\begin{Verbatim}
def hello_world():
    print("Hello, World!")
\end{Verbatim}

You can also include options such as fontsize, linenos (line numbers), etc.

\begin{Verbatim}[fontsize=\small,frame=single]
def hello_world():
    print("Hello, World!")
\end{Verbatim}

The fancyvrb package also provides other environments such as BVerbatim and LVerbatim which are useful for typesetting verbatim text with different formatting options.

Please note that the fancyvrb package is not recommended for large code listings because it can cause issues with line breaks and spacing. But it’s a good choice for small code snippets and text.

How to use listingsutf8 package

The listingsutf8 package is a LaTeX package that provides support for typesetting source code listings with UTF-8 encoded characters. It is an extension of the listings package and provides the same functionality as the listings package but with the added capability to handle UTF-8 encoded characters.

To use the listingsutf8 package in your LaTeX document, you will need to add the following lines to your preamble:

\usepackage{listingsutf8}

Then, you can use the lstlisting environment to insert code listings in your document. The basic syntax is as follows:

\begin{lstlisting}[options]
    code
\end{lstlisting}

Where options are any additional options you want to pass to the package.

For example, the following code will insert a listing of Python code with the default options:

\begin{lstlisting}[language=Python]
def hello_world():
    print("Hello, World!")
\end{lstlisting}

You can also include options such as fontsize, linenos (line numbers), etc.

\begin{lstlisting}[language=Python, fontsize=\small, numbers=left]
def hello_world():
    print("Hello, World!")
\end{lstlisting}

The listingsutf8 package provides many other options to customize the appearance of the code listing, such as background color, keywords, and more. It also allows for inputencoding to be UTF-8, so it can handle special characters and non-latin scripts.

Please note that if you are using an older version of LaTeX, you may need to install the listingsutf8 package manually and configure your TeX distribution to find it.