Determinate Loops with the Python for statement Rick

Algorithmic Pattern: The Determinate loop We often need to perform some action a specific

Determinate Loops The determinate loop pattern can be implemented with the Python for loop

For loops • Determinate loops know the number of repetitions before they begin to

Examples n = 3 for lcv in range(n): print(lcv, end =' ') for num

Example loop that produces an average n = int(input('Average how many numbers? ')) sum

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Determinate Loops with the Python for statement Rick Mercer

Algorithmic Pattern: The Determinate loop We often need to perform some action a specific number of times: Produce 89 paychecks — Count down to 0 (take 1 second of the clock) — Compute grades for 81 students — Visit every element in a list — The determinate loop pattern – repeats some action a specific number of times – iterates over all elements in a sequence

Determinate Loops The determinate loop pattern can be implemented with the Python for loop We use this pattern so often, there is a statement for<var> in <sequence> : <body> for integer in range(3): print(integer)

For loops • Determinate loops know the number of repetitions before they begin to loop • How many employees, or students, or. . • The number of lines in a file • Numbers of characters in a string • Number of elements in a list

Examples n = 3 for lcv in range(n): print(lcv, end =' ') for num in range(0, 6, 2): print(num, end =' ') for ch in 'Uof. A': print(ch) list = [1, 2, 3] for integer in list: print(integer, end= ' ')

Example loop that produces an average n = int(input('Average how many numbers? ')) sum = 0; for lcv in range(n): number = eval(input('Number: ')) sum = sum + number; average = sum / n print('Average', average) Sample Dialog Average Number: Average how many numbers? 3 78 89. 5 97 88. 2