\documentclass[12pt]{article} \title{Python: Basics} \author{FOSSEE} \usepackage{listings} \lstset{language=Python, basicstyle=\ttfamily, commentstyle=\itshape\bfseries, showstringspaces=false } \newcommand{\typ}[1]{\lstinline{#1}} \usepackage[english]{babel} \usepackage[latin1]{inputenc} \usepackage{times} \usepackage[T1]{fontenc} \usepackage{ae,aecompl} \usepackage{mathpazo,courier,euler} \usepackage[scaled=.95]{helvet} \begin{document} \date{} \vspace{-1in} \begin{center} \LARGE{Python: Basics}\\ \large{FOSSEE} \end{center} \section{Data types} Complex Numbers \begin{lstlisting} In []: c = 3+4j In []: abs(c) Out[]: 5.0 In []: c.imag Out[]: 4.0 In []: c.real Out[]: 3.0 \end{lstlisting} Boolean \begin{lstlisting} In []: a = False In []: b = True In []: c = True In []: (a and b) or c Out[]: True \end{lstlisting} Strings \begin{lstlisting} In []: w = "hello" In []: print w[0] + w[2] + w[-1] Out[]: hlo In []: len(w) Out[]: 5 In []: w[0] = 'H' # ERROR: Strings are immutable \end{lstlisting} String methods \begin{lstlisting} In []: a = 'Hello World' In []: a.startswith('Hell') # 'a' starts with 'Hell' In []: a.endswith('ld') # 'a' ends with 'ld' In []: a.upper() # all characters to upper case In []: a.lower() # all characters to lower case In []: ''.join(['a', 'b', 'c']) Out[]: 'abc' \end{lstlisting} String formatting \begin{lstlisting} In []: x, y = 1, 1.234 In []: 'x is %s, y is %s' %(x, y) Out[]: 'x is 1, y is 1.234' \end{lstlisting} Arithmetic Operators \begin{lstlisting} In []: 45 % 2 # Modulo operator Out[]: 1 In []: 1234567891234567890 ** 3 # Power In []: a = 5 In []: a += 1 In []: a *= 2 \end{lstlisting} String Operations \begin{lstlisting} In []: s = 'Hello' In []: p = 'World' In []: s + p Out[]: 'HelloWorld' In []: s * 4 Out[]: 'HelloHelloHelloHello' \end{lstlisting} Relational and Logical Operators \begin{lstlisting} In []: p, z, n = 1, 0, -1 In []: p == n Out[]: False In []: p >= n Out[]: True In []: n < z < p Out[]: True In []: p + n != z Out[]: False \end{lstlisting} Built-ins \begin{lstlisting} In []: int(17 / 2.0) Out[]: 8 In []: float(17 / 2) Out[]: 8.0 In []: str(17 / 2.0) Out[]: '8.5' In []: round( 7.5 ) Out[]: 8.0 \end{lstlisting} Console Input \begin{lstlisting} In []: a = raw_input('Enter a value: ') Enter a value: 5 \end{lstlisting} \section{Conditionals} \typ{if} \begin{lstlisting} In []: x = int(raw_input("Enter an integer:")) In []: if x < 0: ...: print 'Be positive!' ...: elif x == 0: ...: print 'Zero' ...: elif x == 1: ...: print 'Single' ...: else: ...: print 'More' \end{lstlisting} Ternary Operator \begin{lstlisting} In []: a = raw_input('Enter number(Q to quit):') In []: num = int(a) if a != 'Q' else 0 \end{lstlisting} \end{document}