Introduction to Computer Science: Python Programming Basics

1. CSCI 1001 overview of computer science PYTHON V

2. ages = [20, 18, 17, 26] 17 in ages ages.index(17) sum(ages) range(0,10,2)

3. ‘abc’ in ‘abcdefg’ ‘how are you’[4:7] s = ‘Mr. Spock’ s[0:2] = ‘Dr’ #Won’t work ‘do re mi faso’.find(‘mi’) for s in ‘i can hazcheez’: print s.upper(),

4. d = {} # empty dictionary d = {‘nishi’:4, ‘lnp’:1} d[‘nishi’] d[‘neshek’] # KeyError ‘neshek’ in d d[‘neshek’] = 1 len(d)

5. d = {‘nishi’:4, ‘lnp’:1} d.keys() d.values() d.items() del d[‘lnp’] # in St. Louis dict.fromkeys([1,2,3],’a’)

6. def common(alice, bob): cs = [] for a in alice: if a in bob: cs.append(a) return cs def common2(as, bs): cs = [] d = dict.fromkeys(bs,True) for a in as: if a in d: cs.append(a) return cs

7. fileName = raw_input(“file name: ") f = open(fileName) sum = 0 numLines = 0 for currentLine in f: sum = sum + len(currentLine) numLines = numLines + 1 print "Number of lines: ", numLines if numLines != 0: print "Avg length:", sum/numLines

8. import urllib url = raw_input(“input the url: ") u = urllib.urlopen(url) sum = 0 numLines = 0 for currentLine in u: sum = sum + len(currentLine) numLines = numLines + 1 print "Number of lines: ", numLines if numLines != 0: print "Average line length: ", sum/numLines

9. http://cs1001.us/ Please read Sections 3.3 and 3.4 for Wednesday