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diff --git a/basic_python/practice_control_flow.tex b/basic_python/practice_control_flow.tex new file mode 100644 index 0000000..b0ff7a2 --- /dev/null +++ b/basic_python/practice_control_flow.tex @@ -0,0 +1,372 @@ +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% Tutorial slides on Python. +% +% Author: FOSSEE +% Copyright (c) 2009-2017, FOSSEE, IIT Bombay +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\documentclass[14pt,compress]{beamer} + +\input{macros.tex} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% Title page +\title[Basic Python]{Practice exercises: Control flow} + +\author[FOSSEE Team] {The FOSSEE Group} + +\institute[FOSSEE -- IITB] {Department of Aerospace Engineering\\IIT Bombay} +\date[] {Mumbai, India} +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% DOCUMENT STARTS +\begin{document} + +\begin{frame} + \titlepage +\end{frame} + +\begin{frame}[fragile,plain] + \frametitle{Note: Python 2.x and 3.x} + + If you are using Python 2.x + \begin{itemize} + \item Use \typ{raw\_input} instead of \typ{input} + \item Use the following for \typ{print} + \end{itemize} + \begin{lstlisting} +from __future__ import print_function +\end{lstlisting} +\end{frame} + +\begin{frame}[plain] + \frametitle{Exercise: simple \typ{if}} + \begin{enumerate} + \item Ask the user to enter an integer + \item If the number is positive, print "Positive" + \item If the number is negative, say -10 print:\\ "Negative of 10" + \item If the number is zero, print "Zero" + \item Finally, print "Done" + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + x = int(input()) + if x < 0: + print("Negative of", abs(x)) + elif x > 0: + print("Positive") + else: + print("Zero") + print("Done") +\end{lstlisting} +\end{frame} + +\begin{frame}[plain] + \frametitle{Exercise: simple \typ{if} 2} + \begin{enumerate} + \item Ask the user to enter two integers, one on each line say \typ{x} and \typ{y} + \item If \typ{x} is larger than \typ{y} print, "first", store the value of \typ{x} in a + variable \typ{highest} + \item If \typ{y} is larger than \typ{x} print, "second", store the value of \typ{y} in a + variable \typ{highest} + \item If they are equal, print "same", store either as the \typ{highest} + \item Finally, print the square of the \typ{highest} + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + x = int(input()) + y = int(input()) + if x > y: + print("first") + highest = x + elif y > x: + print("second") + highest = y + else: + print("same") + highest = x + print(highest*highest) +\end{lstlisting} +\end{frame} + + +\begin{frame}[plain] + \frametitle{Simple \typ{while} loop 1} + \begin{enumerate} + \item Use a while loop to print the numbers from 1 to 10 + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + x = 1 + while x < 11: + print(x) + x += 1 +\end{lstlisting} +\end{frame} + +\begin{frame}[plain] + \frametitle{Simple \typ{while} loop 2} + \begin{enumerate} + \item Use a while loop to print the odd numbers from 1 to 10 + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + x = 1 + while x < 11: + print(x) + x += 2 +\end{lstlisting} +\end{frame} + +\begin{frame}[plain] + \frametitle{Simple \typ{while} loop 2} + \begin{enumerate} + \item Use a while loop to generate the numbers from 1 to 10 + \item If a number divisible by 3 is found, print *** + \item If a number divisible by 5 is found, print ***** + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + x = 1 + while x < 11: + if x%3 == 0: + print('***') + elif x%5 == 0: + print('*****') + else: + print(x) + x += 1 +\end{lstlisting} +\end{frame} + +\begin{frame}[plain] + \frametitle{Simple \typ{while} loop 3} + \begin{enumerate} + \item Use a while loop to generate the numbers from 10 to 1 + \item For each number, print that many * characters + \item That is, if the number is 1 print *, if the number is 3, print *** etc. + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + x = 10 + while x > 0: + print('*'*x) + x -= 1 +\end{lstlisting} +\end{frame} + +\begin{frame}[plain,fragile] + \frametitle{Simple \typ{while} loop 4} + \begin{enumerate} + \item Ask the user for an integer, \typ{n} (>=2) + \item Use a while loop to print \typ{n} numbers uniformly spaced between 0 and 1 + \item Include both 0 and 1 + \end{enumerate} + For example if the user entered 3, print + \begin{lstlisting} + 0.0 + 0.5 + 1.0 + \end{lstlisting} + +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + n = int(input()) + dx = 1.0/(n-1) + x = 0.0 + while x < (1.0-dx/2): + print(x) + x += dx + print(1.0) +\end{lstlisting} +\end{frame} + +\begin{frame}[plain,fragile] + \frametitle{Simple \typ{for} loop 1} + \begin{enumerate} + \item Ask the user for an integer + \item Use a for loop to generate the multiplication table for the number (up + to 10) + \end{enumerate} + If the user entered 5, print the following + \begin{lstlisting} + 5 x 1 = 5 + 5 x 2 = 10 + 5 x 3 = 15 + ... + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + n = int(input()) + for i in range(1, 11): + print(n, 'x', i, '=', n*i) +\end{lstlisting} +\end{frame} + +\begin{frame}[plain,fragile] + \frametitle{\typ{for} loop Fibonacci} + \begin{enumerate} + \item Ask the user for an integer, \typ{n} (>=1) + \item Print the first \typ{n} numbers of the Fibonacci sequence + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + n = int(input()) + a, b = 0, 1 + print(a) + for i in range(n-1): + print(b) + a, b = b, a+b +\end{lstlisting} +\end{frame} + + +\begin{frame}[plain,fragile] + \frametitle{\typ{for} loop over list 1} + \begin{enumerate} + \item Ask the user for an integer, \typ{n} + \item Use the range to create numbers from 1 to \typ{n} + \item Print each value in this in a separate line + \end{enumerate} + For example let us say user enters \typ{3}, print + \begin{lstlisting} + 1 + 2 + 3 + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + n = int(input()) + for x in range(1, n+1): + print(x) +\end{lstlisting} +\end{frame} + + +\begin{frame}[plain,fragile] + \frametitle{\typ{for} loop over array} + \begin{enumerate} + \item Ask the user for an integer, \typ{n} + \item Use numpy's \typ{linspace} to create n points from 1 to 2 + \item Print each value in this in a separate line + \end{enumerate} + For example let us say user enters \typ{3}, print + \begin{lstlisting} + 1.0 + 1.5 + 2.0 + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + from numpy import linspace + n = int(input()) + data = linspace(0, 1, n) + for x in data: + print(x) +\end{lstlisting} +\end{frame} + + +\begin{frame}[plain,fragile] + \frametitle{\typ{for} loop over list 2} + \begin{enumerate} + \item Ask the user for an list of fruits separated by a space + \item Print each fruit in a separate line + \end{enumerate} + For example let us say user enters \typ{apple, pear}, print + \begin{lstlisting} + apple + pear + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + fruits = input() + fruits = fruits.split(',') + for fruit in fruits: + print(fruit) +\end{lstlisting} +\end{frame} + +\begin{frame}[plain,fragile] + \frametitle{\typ{for} loop over string} + \begin{enumerate} + \item Ask the user for a string + \item Print each character of the string using a for loop + \end{enumerate} + For example let us say user enters \typ{box}, print + \begin{lstlisting} + b + o + x + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} + s = input() + for char in s: + print(char) +\end{lstlisting} +\end{frame} + +\begin{frame}[plain,fragile] + \frametitle{Exercise: Fibonacci divisible by 4} + \begin{enumerate} + \item Find the first number in the Fibonacci sequence divisible by 4 but > 8 + and less than 500. + \end{enumerate} +\end{frame} + +\begin{frame}[fragile,plain] +\frametitle{Solution} +\begin{lstlisting} +a, b = 0, 1 +while b < 500: + if b % 4 == 0 and b > 8: + print(b) + break + a, b = b, a+b +\end{lstlisting} +\end{frame} + + +\end{document} |