The Zen of Python

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The Zen of Python

• gtgtgt import this

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What makes a good program?
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Where we are

• Mock exam next week, period 4
• Will be screen based, requiring coding
• Then five and a half weeks between half term and
  Easter.
• And three weeks before your real exam Monday
  11th May

Most of you need practice. Just practice. So
please come on Wednesday
4
Miss Matthews Task

• Input two values, height and width
• Calculate (heightwidth)/2 and output the result
• Simple . but ..
• Everyone got it wrong. Why?

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Python division

• What is 2/3?
• Try it .. gtgtgt print 2/3

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Import from the future

• from __future__ import division
• Or
• float(width)

Now fix it!
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Turn this into a function

• Objective .
• Create a function
• With two arguments length and width
• Get the value back, (lengthwidth) / 2
• Need the keyword return

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Whats wrong with this?

• def absolute_value(x)
• if x lt 0
• return -x
• if x gt 0
• return x

Now do it!
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The docstring

• def myweirdfunction(length)
• Draws a line of breadcrumbs which the cursor
  has to follow takes single integer argument
  length
• dostuff
• Print myweirdfunction.__doc__

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Turn it into a module

• Main code section
• def main()
• do stuff
• if __name__ __main__
• main()

Try it out
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Writing a good program

• Structure
• Modules
• Functions
• Documentation strings
• Highlighting the actual program

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The Zen of Python

• gtgtgt import this