october 14 notes

 Lists >>> measurement1 = 43.43 >>> instructors = [„michelle‟, „dan‟, „diane‟, >>> measurement2 = 109.34 „andrew‟, „giovanna‟] >>> measurement3 = 123.34 >>> type(instructors) >>> measurements = [43.43‟, 109.34, 123.34] >>> type(measurements) >>> type (instructors[2]) >>> measurements[0] >>> student = ['John Reed', 'Trinity College', 43.34 987632345, 3.45] >>> measurements[1] >>> type(student) 109.34 >>> measurements[2] >>> type (student[0]) 123.43 >>> measurements[-1] >>> type (student[2]) 123.43 >>> measurements[5] >>> type (student[-1]) o Mutability >>> id(instructors) 546312 >>> instructors[2] = „jen‟ #mutable >>> instructors [„michelle‟, „dan‟, „jen‟, „andrew‟, „giovanna‟] >>> id(instructors) 5464312 >>> s = “can‟t do this” >>> s[2] = „x‟ # strings immutable >>> instructors.append(„diane‟) #changes the list, does not create a new one >>> instructors [„michelle‟, „dan‟, „jen‟, „andrew‟, „giovanna‟, „diane‟] >>> instructors.append(65.43) >>> instructors [„michelle‟, „dan‟, „jen‟, „andrew‟, „giovanna‟, „diane‟, 65.43] >>> id(instructors) 5464312 >>> result = instructors.append(„xxx‟) print result None o Lists and built in functions >>> len(instructors) 8 #number of strings in the list >>> measurements [43.34, 109.34, 123.43] >>> max(measurements) 123.43 >>> min(instructors) 43.34 >>> max(instructors) „xxx‟ >>> instructors ['michelle', 'dan', 'jen', 'andrew', 'giovanna', 'diane', 65.43, 'xxx'] >>> min(instructors) 65.43 >>> instructors[-2] = 'paul' >>> instructors ['michelle', 'dan', 'jen', 'andrew', 'giovanna', 'diane', 'paul', 'xxx'] >>> min(instructors) 'andrew' >>> max(instructors, measurements) #max of 2 lists return list w/ max first value ['michelle', 'dan', 'jen', 'andrew', 'giovanna', 'diane', 'paul', 'xxx'] >>> sum(measurements) 276.11 >>> sum(instructors) o Some list methods >>> L = [„a‟, „b‟, „c‟, „d‟] >>> L.append(„e‟) [„a‟, „b‟, „c‟, „d‟, „e‟] >>> L.insert(2, „new‟) >>> L [„a‟, „b‟, „new‟, „c‟, „d‟] >>> L.insert(len(L), „fun‟] >>> L [„a‟, „b‟, „new‟, „c‟, „d‟, „fun‟] >>> L.insert(-1, „wow‟) [„a‟, „b‟, „new‟, „c‟, „d‟, „wow‟, „fun‟] >>> L.insert(999, „www‟) #just a higher number, even out of index [„a‟, „b‟