Summary: Python

Read the summary and the most important questions on Python

• Tutorial A1 Numeric

  This is a preview. There are 8 more flashcards available for chapter 04/09/2016
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• Python has the standard types (4)

  int, 
  float, 
  long, 
  complex

• 'Arithmetic' operators: floor division(//) en remainder(%)

  
  a // b is the largest multiple of 1 (or 1.0) equal to or below a / b
  
  remainder with division: a % b = (a / b – a // b) * b
  voorbeeld: 10//4 = 2 met remainder ((2.5-2)*4)=2 

• 'Arithmetic' operators: exponentiation (**)

  standard arithmetic “to the power”: a ** b is “a to the power b”

• 'Arithmetic' operators: unary minus(-) and unary plus(+)

  
  
  negative (with only an operand to the right): –a = 0 – a
  positive (with only an operand to the right): +a = 0 + a

• 'Arithmetic' operators: bitwise and (&)bitwise or (|)bitwise xor (^)

  low level operation on int and long
  
  Bitwise XOR sets the bits in the result to 1 if either, but not both, of the corresponding bits in the two operands is 1.
  
  Example 1
  
  >>> bin(0b1111 ^ 0b1111) '0b0' >>> bin(0b1111 ^ 0b0000) '0b1111' >>> bin(0b0000 ^ 0b1111) '0b1111' >>> bin(0b1010 ^ 0b1111) '0b101'

• for importing module math type:

       import math

• Tutorial A2 String

  This is a preview. There are 12 more flashcards available for chapter 05/09/2016
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• String (voorbeeld lower, upper , count en varabele toewijzen)

  low = s.lower() -> ('some mixed case string')
  low.count('e') == 3
  up = s.upper() -> ('SOME MIXED CASE STRING')
  up.count('e') == 3

• Tutorial A3 def function

  This is a preview. There are 3 more flashcards available for chapter 06/09/2016
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• opbouw functie (function heading en function body)

  The first line is called the function heading; the rest of the function is the function body. The function heading begins with the keyword “def” and ends with a colon (“:”). It states the name of the function and, within parentheses, the parameters.
  
  Inside the function body, the names of the parameters can be used like variables that have been assigned some value. 
  
  def area_rectangle (x_lo, x_hi, y_lo, y_hi):   
      width = x_hi - x_lo
      height = y_hi - y_lo     
      area = width * height    
      return area

• defineren en oproepen functie

  def area_rectangle(x_lo, x_hi, y_lo, y_hi):
      width = x_hi - x_lo 
      height = y_hi - y_lo      
      area = width * height     
      return area
  
  oproepen functie met gewenste waarde zier er zo uit: 
  area_rectangle(3, 7, 2, 8)

• It is bad practice as well to let a function do a computation and print the result as well.

   The result cannot be used in any other way when it has been printed only!
  (Printing and returning as well is even worse – don’t do it.)