Class 24 — Wednesday October 24

Reaching an understanding with functions

Practice makes perfect — Is more than a platitude — Take it to your heart

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Look both ways

• Back or ahead

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Agenda

• Another try at functions

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Example de jeur — module primal

• Code: primal.py

• Function is_factor( x, y )

• Parameters x and y are integers. The function returns whether y is a factor of x.

• Function are_relative_primes( x, y )

• Parameters x and y are integers. The function returns whether x and y are relatively prime; i.e., whether y is not a factor of x and vice-versa.

• Function is_prime( x )

• Parameter x is an integer. The function returns whether x is prime; i.e., its only factors are 1 and itself

• Slides: PDF

• Tester: factoid.py

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Homework module take_two

• Code: take_two.py

• Function signum( x )

• Function parameter x is a numeric value. The function returns integer -1, 0, or 1 depending respectively whether x is negative, zero, or positive. The function does not print any output.

• Function mid( s )

• Function parameter s is a string. If the length of string s is odd, the function returns the middle character of s; otherwise, the function returns the two middle characters of s. The function does not print any output.

• Tester: taken.py

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To do

• Review artifacts and prior function materials

• Complete homework

 

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© 2019 Jim Cohoon

Resources from previous semesters are available.