Python - Dictionaries

Python module Y107

Dictionaries

Exercises, examples and other material relating to training module Y107. This topic is presented on public courses Learning to program in Python, Python Programming

Lists and tuples are collections of data values held in an object in which they can be referenced by a position number. Dictionaries are mutable collections of objects in which data values can be looked up name.

Related technical and longer articles

Python List, Python Tuple, Python Dictionary

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Examples from our training material

coin.py	Class used by dictionary with object key example
d1.py	Defining and looking up in a dictionary
d2.py	Looping through all the elements of a dictionary
d3.py	Can I sort a dictionary?
dfp	Optional, list and dictionary params
file_2nd	Analysing blog accesses
marie.data	data file with duplicated lines
nx	Dictionary of objects - exercise and sample answer
pax_month.py	Unique visitors / visited pages per month
pocket.py	dictionary with object keys - example
pred.py	Illustration of a program that would benefit from dictionaries
pres.py	Is a key used in a disctionary?
pycounter	counting words using dictionary
pyset	listing words using set
slowcoach	Analysing visit lengths to web site - no cache
snork	Variable scope when sorting a dictionary by value
soccer.data	Soccer League table
soccer_py	Soccer - league table, old v new point system
topsk	counting occurrences in a file
u0	report unique lines from file
u1	Report each line from a file
u2	count of each line in a file, sorted by count
uniquise	Sort all lines in a file, sort by frequency, list lines they occur on
visitors	Analysing visit lengths to web site - using cache
zip-it.py	Joining 2 lists into a dictionary

Pictures

Practical session on a Python course

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from http://www.training-notes.co.uk.

Topics covered in this module

Why do we need dictionaries?.
Defining and using a dictionary.
Hashing and Sorting.
Checking whether an itemÕs in a dictionary.
Using other objects as dictionary keys.

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