162 \frametitle{Functions: examples}

   162 \frametitle{Functions: Definition}

   163   \begin{lstlisting}

   163 \begin{itemize}

   164 def signum( r ):

   164   \item \kwrd{def} keyword

   165     """returns 0 if r is zero

   165   \item 

   166     -1 if r is negative

   166 \end{itemize}

   167     +1 if r is positive"""

   168     if r < 0:

   169         return -1

   170     elif r > 0:

   171         return 1

   172     else:

   173         return 0

   174   \end{lstlisting}

   180 def pad( n, size ): 

   172 In [35]: def plot_sinx():

   181     """pads integer n with spaces

   173    ....:     x = linspace(0, 2*pi, 100)

   182     into a string of length size

   174    ....:     plt.plot(x, sin(x))

   183     """

   175    ....:     plt.show()

   184     SPACE = ' '

   176    ....:    

   185     s = str( n )

   177 

   186     padSize = size - len( s )

   178 In [36]: plot_sinx()

   187     return padSize * SPACE + s