--- a/getting-started-strings/slides.org Wed Nov 10 10:24:03 2010 +0530
+++ b/getting-started-strings/slides.org Wed Nov 10 10:47:21 2010 +0530
@@ -18,7 +18,7 @@
#+LaTeX_HEADER: commentstyle=\color{red}\itshape, stringstyle=\color{darkgreen},
#+LaTeX_HEADER: showstringspaces=false, keywordstyle=\color{blue}\bfseries}
-#+TITLE: Accessing parts of arrays
+#+TITLE:
#+AUTHOR: FOSSEE
#+EMAIL:
#+DATE:
@@ -30,81 +30,38 @@
#+OPTIONS: TeX:t LaTeX:nil skip:nil d:nil todo:nil pri:nil tags:not-in-toc
* Outline
- - Manipulating one and multi dimensional arrays
- - Access and change individual elements
- - Access and change rows and columns
- - Slicing and striding on arrays to access chunks
- - Read images into arrays and manipulations
-* Sample Arrays
- #+begin_src python
- In []: A = array([12, 23, 34, 45, 56])
-
- In []: C = array([[11, 12, 13, 14, 15],
- [21, 22, 23, 24, 25],
- [31, 32, 33, 34, 35],
- [41, 42, 43, 44, 45],
- [51, 52, 53, 54, 55]])
-
- #+end_src
+*** Defining strings
+*** Concatenation
+*** Accessing individual elements
+*** Immutability of strings
* Question 1
- Change the last column of ~C~ to zeroes.
+ Obtain the string ~%% -------------------- %%~ (20 hyphens) without
+ typing out all the twenty hyphens.
* Solution 1
#+begin_src python
- In []: C[:, -1] = 0
+ s = "%% " + "-"*20 + " %%"
#+end_src
* Question 2
- Change ~A~ to ~[11, 12, 13, 14, 15]~.
+ Given a string, ~s~ which is ~Hello World~ , what is the output of::
+ #+begin_src python
+ s[-5]
+ s[-10]
+ s[-15]
+ #+end_src
* Solution 2
#+begin_src python
- In []: A[:] = [11, 12, 13, 14, 15]
- #+end_src
-* squares.png
- #+begin_latex
- \begin{center}
- \includegraphics[scale=0.6]{squares}
- \end{center}
- #+end_latex
-* Question 3
- - obtain ~[22, 23]~ from ~C~.
- - obtain ~[11, 21, 31, 41]~ from ~C~.
- - obtain ~[21, 31, 41, 0]~.
-* Solution 3
- #+begin_src python
- In []: C[1, 1:3]
- In []: C[0:4, 0]
- In []: C[1:5, 0]
- #+end_src
-* Question 4
- Obtain ~[[23, 24], [33, -34]]~ from ~C~
-* Solution 4
- #+begin_src python
- In []: C[1:3, 2:4]
- #+end_src
-* Question 5
- Obtain the square in the center of the image
-* Solution 5
- #+begin_src python
- In []: imshow(I[75:225, 75:225])
- #+end_src
-* Question 6
- Obtain the following
- #+begin_src python
- [[12, 0], [42, 0]]
- [[12, 13, 14], [0, 0, 0]]
- #+end_src
-
-* Solution 6
- #+begin_src python
- In []: C[::3, 1::3]
- In []: C[::4, 1:4]
+ 'W'
+ 'e'
+ IndexError
#+end_src
* Summary
- You should now be able to --
- - Manipulate 1D \& Multi dimensional arrays
- - Access and change individual elements
- - Access and change rows and columns
- - Slice and stride on arrays
- - Read images into arrays and manipulate them.
+ In this tutorial we have learnt
+ + How to define strings
+ + Different ways of defining a string
+ + String concatenation and repetition
+ + Accessing individual elements of the string
+ + Immutability of strings
+
* Thank you!
#+begin_latex
\begin{block}{}