Assignment 20 — function implementation

Due Monday, March 25

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Module take_it_away.py

• Your module should implement the below three functions.

• A simple tester taken.py is available.

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Function donut( d, h )

• Function parameters d and h are numerics. Returns the volume of a donut whose width is d and whose hole width is h. The formula for donut volume is

π² ( d² - h² ) ( d - h ) / 32

The π in the above formula is pi. Remember the best estimate of π in Python is math.pi.

• A run of of the tester should produce output

donut( 4.5, 1.75 ): 14.577906891257474:

donut( 3.75, 2.15 ): 4.658453277314178

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Function signum( x )

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

• A run of of the tester should produce output

f( -3.5 ): -1

f( 0 ) : 0

f( 5 ): 1

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Function mid( s )

• Function parameter s is a string. If the length of 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.

• For example, mid( 'abcdef' ) evaluates to 'cd' and mid( 'abcde' )

• A run of of the tester should produce output

mid( 'abcdef' ): 'cd'

mid( 'abcde' ): 'c'