1. Module 2 - Part 1 Variables, Assignment, and Data Types
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CSE 1321 Module 2

2. Python Keywords
False def if raise None del import return True elif in try and else is while as except lambda with assert finally nonlocal yield break for not class from or continue global pass
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CSE 1321 Module 2

3. Printing strings in Python (review)
print (‘Whatever you are, be a good one.’)
It’s just print!
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CSE 1321 Module 2 3

4. Pseudocode
CLASS CountDown BEGIN METHOD Main() BEGIN s1 ← "Three... " s2 ← "Two... " s3 ← "One... " s4 ← "Zero... " PRINT(s1 + s2 + s3 + s4 + "Liftoff!") PRINTLINE()
PRINT("Houston, we have a problem.") END Main END CountDown
Output:
Three... Two... One... Zero... Liftoff! Houston, we have a problem. Ps
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CSE 1321 Module 2 4

5. Python Output: def main(): s1 = 'Three... ' s2 = 'Two... '
s3 = 'One... '
s4 = 'Zero... '
print (s1 + s2 + s3 + s4 + 'Liftoff!')
print ()
print ('Houston, we have a problem.')
if __name__ == '__main__':
  main()
Output:
Three... Two... One... Zero... Liftoff! Houston, we have a problem.
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CSE 1321 Module 2 5

6. Escape Sequences
Printing and escape sequence prints a special character in an output string.
Common escape sequences:
\b backspace. (e.g “B\bsecz\bret” prints what?)
\t tab
\n newline
\r carriage return
\” double quote
\’ single quote
\\ backslash
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CSE 1321 Module 2 6

7. Python # Escape sequences def main():
print ('Roses are red,\n\tViolets are blue,\n' +
'Sugar is sweet,\n\tBut I have \'commitment issues\',\n\t' +
'So I\'d rather just be friends\n\t At this point in our ' + 'relationship.')
if __name__ == '__main__':
  main()
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CSE 1321 Module 2 7

8. Ps Pseudocode // Prints the number of keys on a piano. CLASS PianoKeys
BEGIN
METHOD Main()
BEGIN keys ← 88
PRINT("A piano has " + keys + " keys.") END Main
END PianoKeys
Output: A piano has 88 keys. Ps
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CSE 1321 Module 2 8

9. Python #prints the number of keys on a piano. def main(): keys = 88
print("A piano has ", keys, " keys.");
if __name__ == '__main__':
main()
Output: A piano has 88 keys.
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CSE 1321 Module 2 9

10. Pseudocode
// Print the number of sides of several geometric shapes.
CLASS Geometry
BEGIN
METHOD Main()
sides ← PRINT("A heptagon has " + sides + " sides.") sides ← 10
PRINT("A decagon has " + sides + " sides.")
sides ← 12
PRINT("A dodecagon has " + sides + " sides.")
END Main
END Geometry
Output:
A heptagon has 7 sides.
A decagon has 10 sides.
A dodecagon has 12 sides. Ps
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CSE 1321 Module 2 10

11. Python def main(): sides = 7 # declare and initialize
print("A heptagon has ", sides, " sides.")
sides = 10 # assignment statement
print("A decagon has ", sides, " sides.")
sides = 12 # assignment statement
print("A dodecagon has ", sides, " sides.")
if __name__ == '__main__':
main()
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CSE 1321 Module 2 11