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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Functions And Software Development Workflow
Some key concepts
- Function signature
Step1:  Put the function in a python module
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Python Code:
5 / 3
5 % 3
import numpy as np
value = 4
is_prime = True
upper = int(np.ceil(np.sqrt(value)))
for divisor in range(2, upper+1):
    if value % divisor == 0:
        is_prime = False
        break
print(is_prime)
value = 4
def isPrime(value):
    is_prime = True
    upper = int(np.ceil(np.sqrt(value)))
    if value == 2:  # THIS IS TERRIBLE
        return is_prime
    for divisor in range(2, upper+1):
        if value % divisor == 0:
            is_prime = False
            break
    return is_prime
for val in range(2, 20):
    print("%d: %d" % (val, isPrime(val)))
Explanation: Functions And Software Development Workflow
Some key concepts
- Function signature: its name, inputs, and outputs
- Use notebooks for (a) exploratory development and (b) results presentation. Don't use notebooks to contain significant code.
- To use a function inside a notebook, you must import its containint module.
Iterative development of a function
Construct a function that tests if a number is prime.
End of explanation
import is_prime
is_prime.isPrime(4)
for val in range(2, 20):
    print("%d: %d" % (val, is_prime.isPrime(val)))
Explanation: Put the function in a python module
End of explanation
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