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Explore key concepts in Python programming like data types, variables, functions, and control structures. Learn to work with lists, tuples, dictionaries, libraries, and writing effective code with comments. Dive into IF/ELIF/ELSE statements, loops like WHILE and FOR, and how to find maximum values in Python.
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CSCI 1001 overview of computer science PYTHON II
Need to Know Data types Expressions Variables Functions Input and Output Libraries Control structures
functions: def area(r): return 3.14 * r * r def example(n): for i in range(1,n+1): print i return example(10) • example(1)
lists: [‘a’, ‘b’, ‘c’], [] tuples: (‘a’, ‘b’, ‘c’) dictionaries: d = {} d[‘key’] = ‘value’
libraries: import math print math.pi, math.log(2) import time print time.time(), time.ctime() import random print random.random() a = range(0,10) random.shuffle(a) http://docs.python.org/library/index.html
Comments def max(a1, a2): # find the max of a1,a2 if a1 > a2: return a1 else: return a2 def silly(s): return s + “# still here!” Comments help people to read code
IF/ELIF/ELSE if x < 18: print ‘kid’ elifx < 21: print ‘not a kid’ elifx < 34: print ‘grown up’ else: print ‘really old’
WHILE i = 0 while i < 10: print i i = i+1 print ‘finally, i=’, i
FOR for i in range(0,10): print i # down here, what’s i?
finding maximum input: integers a1,a2,…,an output: max 1. set max = a1 2. set i = 1 3. while i ≤ n do 4. if ai > max then 5. set max = ai 6. set i = i+1 7. output max and stop
in python… def find_max(a) n = len(a) i = 0 max = a[0] while i < n: if a[i] > max: max = a[i] i += 1 return max
http://cs1001.us/ Please read Sections 3-5 of the Python chapter for Friday