dictionaries and strings in this we will mainly focus on two data typesdictionaries and strings dictionaries can be considered generalization of the list data typewhere the indices are not required to be integers we have already used strings multiple times in the previous but we will revisit them here to introduce number of new and useful functions both dictionaries and strings are particularly useful for reading and processing text filesand many of our examples will be related to such applications dictionaries in mathematicsa mapping is relation between objects or structures that often takes the form of function mapping is rule that assigns unique value (xto given input mappings are also widely used in computer science and can be implemented in many different ways for instancea python list can be viewed as mapping between integers (list indicesand the objects contained in list more general mappings can be implemented using functions and if-testsfor instancethe mapping 'norway--'oslo'sweden--'stockholm'france--'pariscould be implemented in python as functiondef ( )if ='norway'return 'osloelif ='sweden'return 'stockholmelif ='france'return 'paris(cthe author( sundnesintroduction to scientific programming with pythonsimula springerbriefs on computing