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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. Returns 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]

Flowchart:

Flowchart: Geometric progression.

Visualize Python code execution:

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Python Code Editor:

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Previous: Write a Python program to check if a given function returns True for every element in a list.
Next: Write a Python program to that takes any number of iterable objects or objects with a length property and returns the longest one.

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Python: Tips of the Day

Big Number Readability:

you can separate zeros with underscore (_)

print(2_000_000)
print(2_000_000 +1)

Output:

2000000
2000001