generate-prime-table.py

"""
    Generates the `prime-table.scad` file used by the main
    scad file
"""

### Settings

start_num=0 # The starting and ending numbers we will search for primes.
end_num=5000 # The first should generally be 0.

output_file="prime_table.scad"

column_width = 8 # Number of primes between newlines in the generated SCAD file
display_output = True # Display what we will be placing in the file? Useful for debugging

### Functions / etc

def is_prime(num):
    """Returns True if the number is prime
    else False."""
    if num == 0 or num == 1:
        return False
    for x in range(2, num):
        if num % x == 0:
            return False
    else:
        return True

### Initialization

integer_list = range(start_num,end_num)
prime_list=[]

scadfile_header = f"""
/*
    *** CHANGES TO THIS FILE MAY BE OVERWRITTEN ***

    (Static) prime number list. Generally, you will not want edit this file!
    If you want to change the number of primes, edit and re-run the generator.
    On the last run, this file was generated by the following:
    {__file__}

    *** CHANGES TO THIS FILE MAY BE OVERWRITTEN ***
*/

primes = [
"""

scadfile_footer = f"""
];
/*
    *** CHANGES TO THIS FILE MAY BE OVERWRITTEN ***

    See note at top of file.
*/
"""
### Start Script

# Iterate through all of the integers we generated
for an_integer in integer_list:
    if is_prime(an_integer): # If this one prime? If so...
        prime_list.append(an_integer) # then add it to the list

# Start generating our actual file.
file_contents = scadfile_header

# Generate a comma-seperated list of our numbers
#num_list_string = prime_list.split(",")
#
#num_list_string = ','.join(map(str,prime_list))

# The following section of code exists strictly to make the line lengths in
# our generated .scad file a bit less nuts. We will be making an "outer" list
# that will later be split by newlines, and the inner one will be primes
# seperated by commas.

split_prime_list = [] # the "outer" list - each element is a string of `column_width` primes, seperated by commas

#numbers_string = ""
for x in range(0,len(prime_list),column_width):
    # To  "outer" list, append the relevant section of the prime list, joined by commas
    split_prime_list.append(','.join(
        map(str,prime_list[x: x + column_width]))
    )

# Finish up our string by joining it with commas & newlines
numbers_string=',\n'.join(split_prime_list)

file_contents=scadfile_header + numbers_string + scadfile_footer

if display_output:
    print(file_contents)

with open(output_file,'w') as output_file_obj:
    output_file_obj.write(file_contents)