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#+LaTeX_CLASS: beamer
#+LaTeX_CLASS_OPTIONS: [presentation]
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#+LaTeX_HEADER: commentstyle=\color{red}\itshape, stringstyle=\color{darkgreen},
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#+TITLE:
#+AUTHOR: FOSSEE
#+EMAIL: info@fossee.in
#+DATE:
#+DESCRIPTION:
#+KEYWORDS:
#+LANGUAGE: en
#+OPTIONS: H:3 num:nil toc:nil \n:nil @:t ::t |:t ^:t -:t f:t *:t <:t
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*
#+begin_latex
\begin{center}
\vspace{12pt}
\textcolor{blue}{\huge Dictionaries}
\end{center}
\vspace{18pt}
\begin{center}
\vspace{10pt}
\includegraphics[scale=0.95]{../images/fossee-logo.png}\\
\vspace{5pt}
\scriptsize Developed by FOSSEE Team, IIT-Bombay. \\
\scriptsize Funded by National Mission on Education through ICT\\
\scriptsize MHRD,Govt. of India\\
\includegraphics[scale=0.30]{../images/iitb-logo.png}\\
\end{center}
#+end_latex
* Objectives
At the end of this tutorial, you will be able to,
- Create dictionaries.
- Add and delete data from dictionaries.
- Retrieve data from dictionaries.
- Check for container-ship of keys.
- Iterate over elements.
* Pre-requiste
Spoken tutorial on -
- Basic datatypes and operators
* Overview of Dictionaries
- A dictionary contains meaning of words
- /Word/ is the /key/ here.
- /Meaning/ is the /value/ here.
- A Key-Value pair data structure
- Provide key-value mappings
* Accessing Elements
- syntax
: extensions[key]
* Retrieve keys and values
- ~.keys()~ method
: In []: extensions.keys()
Returns a list of keys in the dictionary.
- ~.values()~ method
: In []: extensions.values()
Returns the list of values in the dictionary.
* Exercise 1
- Print the keys and values in the dictionary one by one.
* Summary
In this tutorial, we have learnt to,
- Create dictionaries namely --
- empty dictionaries
- dictionaries with data.
- Access elements in the dictionaries using the keys.
- Add elements to a dictionary by assigning a value to a key.
- Delete elements from a dictionary by using the function ``del''.
- Retrieve the keys and values by using the methods ``.keys()'' and
``.values()'' respectively.
- Iterate over elements of a dictionary using a ``for'' loop.
* Evaluation
1. Container-ship of values can be checked in a python dictionary
- True
- False
2. Consider the python dictionary
: x = {'a':['a','b','c'], 'b':(1, 2, 3),
: 1:{1:'one', 2:'two'},
: 10:{10:'ten', 11:'eleven'}}
What will the following code return?
~(1, 2, 3) in x.values()~
- True
- False
- Container-ship of values cannot be checked in dictionaries
- The dictionary is invalid
* Solutions
1. False
2. True
*
#+begin_latex
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\textcolor{blue}{\Large THANK YOU!}
\end{center}
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\begin{block}{}
\begin{center}
For more Information, visit our website\\
\url{http://fossee.in/}
\end{center}
\end{block}
#+end_latex
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