Cycle through a list of terms and batch rename files - bash

Question

EDIT: In the course of working on and reediting this question, I was able to get this to work. However, I'm sure there's a better way to do it, so I'm leaving it up to hear from those more experienced.
Periodically I need to reproduce several dozen copies of a few files. For example, given:
company_a_results_30d.py
company_a_results_90d.py
company_a_results_120d.py
company_a_results_all_time.py
I need to make copies where company_a is replaced with company_b, company_c....etc. (The next step is to find and replace a number of terms within the files, but this I have managed to do with a perl script.)
I'm sure this should be possible with a bash script and mv, but I haven't quite got the hang of it. Something like:
#!/usr/bin/env bash
my_array=(company_b company_c company_d)
for i in "${my_array[#]}"
do
for file in *.py
do
cp "$file" "${file/company_a/$i}"
done
done
I'd prefer a solution compatible with zsh, which is what I use.

Answer 1

bash
Slightly modified from the OP's answer:
#!/usr/bin/env bash
set -x # So you can see what's happening - feel free to omit
company_a_files=(company_a*.py) # <== Save the list of files first
my_array=(company_b company_c company_d)
for i in "${my_array[#]}"
do
for file in "${company_a_files[#]}" # <== Use the saved list
do
cp "$file" "${file/company_a/$i}"
done
done
When the inner loop in the OP's answer runs for file in *.py, the glob will pick up whatever company_b &c. files have already been created. So you wind up with a lot of set -x output like:
+ cp company_b_1.py company_b_1.py
cp: 'company_b_1.py' and 'company_b_1.py' are the same file
Instead, save the glob of company_a files into a shell array first, and then
loop over that array.
perl
As a one-liner for Perl 5.14+:
perl -MFile::Copy=copy -E 'for my $file (#ARGV) { copy $file, $file =~ s/company_a/$_/r foreach qw(company_b company_c company_d) }' company_a*.py
The Perl version switches the loop order compared to the bash version. For each file given on the command line (the for ... #ARGV), it copies from that file to each name-modified file in turn (the foreach).
$file =~ s/company_a/$_/r is a non-destructive (/r) replace in $file (the filename) that changes company_a to $_ (the current value from foreach).

Answer 2

This was the solution I came up with:
#!/usr/bin/env bash
my_array=(company_b company_c company_d)
for i in "${my_array[#]}"
do
for file in *.py
do
cp "$file" "${file/company_a/$i}"
done
done