Python: Geometric progression

Python List: Exercise - 244 with Solution

Write a Python program to initialize a list containing the numbers in the specified range where start and end are inclusive and the ratio between two terms is step. Return an error if step equals 1.

• Use range(), math.log() and math.floor() and a list comprehension to create a list of the appropriate length, applying the step for each element.
• Omit the second argument, start, to use a default value of 1.
• Omit the third argument, step, to use a default value of 2.

Sample Solution:

Python Code:

from math import floor, log
def geometric_progression(end, start=1, step=2):
  return [start * step ** i for i in range(floor(log(end / start)
          / log(step)) + 1)] 
print(geometric_progression(256))
print(geometric_progression(256, 3))
print(geometric_progression(256, 1, 4))

Sample Output:

[1, 2, 4, 8, 16, 32, 64, 128, 256]
[3, 6, 12, 24, 48, 96, 192]
[1, 4, 16, 64, 256]

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