204 statistics section? 

   204 Dictionaries are data structures that provide key-value mappings. They are similar to lists except that instead of the values having integer indexes, they have keys or strings as indexes.\\

   205 A simple dictionary can be created by:

   206 \begin{lstlisting}

   207 In []: player = {'Mat': 134,'Inn': 233,

   208           'Runs': 10823, 'Avg': 52.53}

   209 \end{lstlisting}

   210 For above case, value on left of ':' is key and value on right is corresponding value. To retrieve value related to key 'Avg'

   211 \begin{lstlisting}

   212 In []: player['Avg']

   213 Out[]: 52.530000000000001

   214 \end{lstlisting}

   215 \subsection{Element operations}

   216 \begin{lstlisting}

   217 In []: player['Name'] = 'Rahul Dravid' #Adds new key-value pair.

   218 In []: player

   219 Out[]: 

   220 {'Avg': 52.530000000000001,

   221  'Inn': 233,

   222  'Mat': 134,

   223  'Name': 'Rahul Dravid',

   224  'Runs': 10823}

   225 In []: player.pop('Mat') # removing particular key-value pair

   226 Out[]: 134

   227 In [21]: player

   228 Out[21]: {'Avg': 52.530000000000001, 'Inn': 233, 

   229           'Name': 'Rahul Dravid', 'Runs': 10823}

   230 \end{lstlisting}

   231 \textbf{Note:} Duplicate keys are overwritten!\\

   232 \begin{lstlisting}

   233 In []: player['Name'] = 'Dravid'

   234 In []: player

   235 Out[23]: {'Avg': 52.530000000000001, 'Inn': 233, 

   236           'Name': 'Dravid', 'Runs': 10823}

   237 \end{lstlisting}

   238 \subsection{containership}

   239 \begin{lstlisting}

   240 In []: 'Inn' in player

   241 Out[]: True

   242 In []: 'Econ' in player

   243 Out[]: False

   244 \end{lstlisting}

   245 \textbf{Note:} Containership is always checked on 'keys' of dictionary but not 'values'.\\

   246 \subsection{Methods}

   247 \begin{lstlisting}

   248 In []: player.keys() # returns list of all keys

   249 Out[]: ['Runs', 'Inn', 'Avg', 'Mat']

   250 

   251 In []: player.values() # returns list of all values.

   252 Out[]: [10823, 233, 

   253         52.530000000000001, 134]  

   254 \end{lstlisting}