• Intro to Programming
  • 1.  Elements of Programming
    • 1.1  Your First Program
    • 1.2  Built-in Types of Data
    • 1.3  Conditionals and Loops
    • 1.4  Arrays
    • 1.5  Input and Output
    • 1.6  Case Study: PageRank
  • 2.  Functions
    • 2.1  Defining Functions
    • 2.2  Modules and Clients
    • 2.3  Recursion
    • 2.4  Case Study: Percolation
  • 3.  OOP
    • 3.1  Using Data Types
    • 3.2  Creating Data Types
    • 3.3  Designing Data Types
    • 3.4  Case Study: N-Body
  • 4.  Data Structures
    • 4.1  Performance
    • 4.2  Sorting and Searching
    • 4.3  Stacks and Queues
    • 4.4  Symbol Tables
    • 4.5  Case Study: Small World

• Related Booksites
• Web Resources
  • FAQ
  • Code
  • Errata
  • Appendices
    • A.   Python Operator Precedence
    • B.   Writing Clear Code
    • C.   Gaussian Distribution
    • D.   Python Cheatsheet
    • E.   NumPy

Errata, First Printing

CHAPTER 1

p. xiii

p. 4, box at bottom

p. 16, line 9

p. 17, "Assignment Statements" paragraph

p. 24, second paragraph

p. 28, Typical float expressions table

p. 33, caption of table at top

p. 34, "Typical comparison expressions" insert

p. 34, last full paragraph

p. 38, Abbreviation alert

p. 41

p. 45, first line

p. 53, Exercise 1.2.22

p. 53, Exercise 1.2.24

p. 57

if x >= 0:
   stdout.write('not ')
stdout.writeln('negative')

if x >= 0:
   stdio.write('not ')
stdio.writeln('negative')

p. 57

if x >= 0:
   stdout.write('not ')
   stdout.writeln('negative')

if x >= 0:
   stdio.write('not ')
   stdio.writeln('negative')

p. 58

p. 58, "Typical examples of using if statements" insert

p. 60, Flowchart example (while statement)

p. 61, Anatomy of a while loop

p. 63, first paragraph

p. 64, Description of powersoftwo.py

p. 64, Description of powersoftwo.py

p. 69, Flowchart for divisorpattern.py, in the leftmost box

stdio.writeln('  ')

stdio.writeln('* ')

p. 71

p. 71

p. 75, Box describing variables

p. 77

p. 81

p. 82, first paragraph

p. 83

p. 83, last paragraph

p. 84, first (partial) paragraph

p. 84, first full paragraph

p. 84, "An infinite loop (with output)" insert

p. 90, Exercise 1.3.10

p. 90, Exercise 1.3.11

p. 91, Exercise 1.3.13

p. 92, Exercise 1.3.19

p. 92, Exercise 1.3.20

p. 92, Exercise 1.3.20

p. 93, Exercise 1.3.21

p. 93, Exercise 1.3.25

p. 93, Exercise 1.3.26

p. 94, Exercise 1.3.31

p. 95, Exercise 1.3.33

p. 96, Exercise 1.3.37 solution

p. 97, Exercise 1.3.39

p. 101

p. 101

p. 101

p. 102, first code fragment

p. 102, second code fragment

p. 103, Memory representation paragraph

p. 103, Memory representation paragraph

p. 104

p. 105, second paragraph

p. 105, first code fragment

p. 110, table

p. 111, last paragraph

p. 112, "Sampling without replacement paragraph

p. 113, sample.py code listing

p. 116, table

p. 116, table

p. 118

p. 120

p. 122

p. 123, Typical spreadsheet calculations

p. 123, Typical spreadsheet calculations

p. 123

p. 124

p. 125

p. 126

p. 126

p. 130

p. 134, Exercise 1.4.14

p. 144, "Anatomy of a formatted print statement" insert

p. 150, "Description of Program 1.5.2

p. 152, Program 1.5.3

p. 154

p. 167

p. 169

p. 172

p. 177, First answer

p. 179, Exercise 1.5.7

p. 179, Exercise 1.5.8

p. 180, Exercise 1.5.10

p. 183, Exercise 1.5.24

p. 191

p. 192

p. 201

CHAPTER 2

p. 211

p. 214, line 8

p. 211

p. 218, second paragraph

p. 220

p. 220

p. 229

p. 234, inset describing Program 2.1.4

p. 235

p. 235, figure

p. 243, Exercise 2.1.22

p. 262

p. 267, in the table

p. 274, in the "Plotting a sound wave" inset

p. 296, in the "Function call trace for gcd()" insert

p. 303, the 12th line of the output of "python beckett 4"

p. 314, the second line of the ex235() function

p. 315, Exercise 2.3.8

p. 315, Exercise 2.3.8

p. 333, in the text describing Program 2.4.5

p. 339

p. 345, Exercise 2.4.1

p. 348, Exercise 2.4.21

p. 349, Exercise 2.4.22

CHAPTER 3

p. 362

p. 363, in the box showing executions of chargeclient.py

p. 375, first paragraph, sixth line

p. 378

p. 385, Description of end variable

p. 388

p. 391, in the 4th answer

p. 393, Exercise 3.1.1

p. 404, "Anatomy of a constructor" diagram

self._rx = x0
self._rx = x0

self._rx = x0
self._ry = y0

p. 406, first paragraph

p. 409

p. 409

r = math.sqrt(dx*dx + dy*dy)
if r == 0.0: return float('inf')

r = math.sqrt(dx*dx + dy*dy)
if r == 0.0:
    if self._q >= 0.0:
        return float('inf')
    else:
        return float('-inf')

p. 411

p. 413

p. 415

p. 416, at the beginning of the 3rd paragraph

p. 428, Table at bottom

p. 438, Second bullet point

p. 439, First question

p. 442, Exercise 3.2.7

p. 443, Exercise 3.2.8

p. 445, Exercise 3.2.21

p. 456

p. 463

p. 471, third line

p. 482

        2-gram  hash  count  unit  count  unit
        AA         0      0  0         2  0.139
        AC         1      0  0         1  0.070
        AG         2      3  0.397     2  0.139
        AT         3      4  0.530     1  0.070
        CA         4      2  0.265     2  0.139
        CC         5      0  0         2  0.139
        CG         6      1  0.132     6  0.417
        CT         7      0  0         4  0.278
        GA         8      1  0.132     2  0.139
        GC         9      4  0.530     6  0.417
        GG        10      0  0         2  0.139
        GT        11      0  0         4  0.278
        TA        12      3  0.397     0  0
        TC        13      0  0         5  0.348
        TG        14      1  0.132     4  0.278
        TT        15      0  0         6  0.417

p. 483

p. 485

p. 485

    $ python comparedocuments.py 5 10000 < documents.txt
            cons    toms    huck    prej    vect    djia    amaz    actg
    cons    1.00    0.69    0.63    0.67    0.09    0.15    0.19    0.12
    toms    0.69    1.00    0.93    0.89    0.07    0.18    0.19    0.14
    huck    0.63    0.93    1.00    0.83    0.05    0.16    0.16    0.13
    prej    0.67    0.89    0.83    1.00    0.06    0.20    0.20    0.14
    vect    0.09    0.07    0.05    0.06    1.00    0.02    0.19    0.02
    djia    0.15    0.18    0.16    0.20    0.02    1.00    0.11    0.07
    amaz    0.19    0.19    0.16    0.20    0.19    0.11    1.00    0.06
    actg    0.12    0.14    0.13    0.14    0.02    0.07    0.06    1.00

p. 490, second question

p. 499

CHAPTER 4

p. 513, insert

python threesum.py < 1Kints.txt
python threesum.py < 2Kints.txt

python threesum.py < 1kints.txt
python threesum.py < 2kints.txt

p. 530

p. 535

p. 538, Exercise 4.1.14

p. 540, Table

p. 544, Solution to Exercise 4.1.5

p. 550, Exercise 4.1.16

p. 552, Exercise 4.1.31

def no2slash(name):
    for x in range(len(name)):
        if x > 0:
            if (name[x-1] == '/') and (name[x] == '/'):
                for y in range(x+1, len(name)):
                    name[y-1] = name[y]
            else:
                x += 1

def no2slash(name):
    nameList = list(name)
    x = 1
    while x < len(nameList):
        if (nameList[x-1] == '/') and (nameList[x] == '/'):
            for y in range(x+1, len(nameList)):
                nameList[y-1] = nameList[y]
            nameList = nameList[:-1]
        else:
            x += 1
    return ''.join(nameList)

p. 553, Exercise 4.1.32

p. 557, "Finding a hidden number with binary search insert

p. 560, "Binary representation" paragraph

p. 563, Final figure

p. 565, Program 4.2.3

p. 577, first full paragraph

p. 587, Exercise 4.2.22

p. 587, Exercise 4.2.23

p. 596

p. 598, Description of Program 4.3.2

p. 633, Exercise 4.3.46

-    or 3 3 6 None None None not to  not None None
that    4 3 7 None None None not to  not that None

-    or 3 3 6 None None None not to  be None None
that    4 3 7 None None None not to  be that None

p. 633, Exercise 4.3.46

-    or 3 3 6 None None None not to  not None None
that    4 3 7 None None None not to  not that None

-    or 3 3 6 None None None not to  be None None
that    4 3 7 None None None not to  be that None

p. 628, Exercise 4.3.33

p. 664

p. 664

p. 671, Exercise 4.4.17

p. 702, figure

p. 702, figure