In search and replacing using VIM, how do I keep a grouped text and reuse it in the replacement part?

Question

In VIM (edit MacVim snapshot 64), I am looking for a way to convert these lines of text

can_check_steps = 1
can_edit_work_type = 1
can_edit_vendor = 1
can_edit_place = 1

to

'can_check_steps': can_check_steps,
'can_edit_work_type': can_edit_work_type,
'can_edit_vendor': can_edit_vendor,
'can_edit_place': can_edit_place,

I know how to add the leading single quote and convert the = into : with multi-line character replacement (something I learned from this question) and basic search and replace, respectively.

But I can't really figure out how to repeat that the variable name per line. I'm also starting to think there should be a way to do this all in one command using like grouped expressions (using ( and ) to "capture" in regular expression).

I know how to do it in Python with lines of code, but I don't really know how to do it in VIM using the s/search_for_this/replace_that/options format.

---

EDIT:

After reading the answers, why doesn't this work?

^\s*(\w+) = 1\s*$/'\1': \1,/g

For @Jonathan Leffler, :set all in MacVim produces

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Answer 1

That should do the work:

%s/\v(\w+).*/'\1': \1,

I think your query doesn't work because the + symbols needs the slash \ before it. In my query I used the \v 'very magic' option that allows me to skip some slashes.

see :h /magic