How to collect expressions from cells created by Print?

Question

I have a notebook where evaluation of a certain cell produced hundreds of adjacent output cells using Print. I need to create a list containing all expressions from those output cells as elements, and assign the list to a variable without re-running the evaluation.

Could you suggest a way to automate this process to avoid manually copying all expressions?

See this post: http://mathematica.stackexchange.com/q/22584/363 — Chris Degnen, Dec 03 '13 at 19:58

Dr. belisarius · Accepted Answer · 2013-12-03T21:57:44.123

18

The following seems to work, however I think it's not general enough:

At a clean nb, enter:

For[i = 0, i < 4, i++, Print[{i, {33, i}}]]
For[i = 0, i < 4, i++, Print[Graphics[Circle[], ImageSize -> 20]]]

Mathematica graphics

And then retrieve the Print[ ] output as:

c = Cases[NotebookRead /@ Cells[GeneratedCell -> True], Cell[___, "Print", ___]];
ToExpression /@ Cases[c, BoxData[__], {2}]

Mathematica graphics

edited Dec 03 '13 at 21:57

answered Dec 03 '13 at 20:05

Dr. belisarius

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score 2 · Answer 2 · answered Dec 03 '13 at 19:57

2

How about

Block[{Print = Sow},
  Do[Print[i], {i, 1, 1000}] // Reap
]

answered Dec 03 '13 at 19:57

Greg Hurst

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In my case, re-running of the evaluation would take longer that manual copying of expressions from existing cells. – Vladimir Reshetnikov Dec 03 '13 at 22:00
Yes sorry, I didn't read "(without re-running the evaluation)". – Greg Hurst Dec 03 '13 at 22:03

Ray Koopman · Answer 3 · 2013-12-04T07:44:38.193

1

Make each result the argument of a pure function; e.g., (Sow[#]; Print[#])&[whatever], with all the functions inside a Reap. That also lets you format the printed output in a way that might be easier for a person to read but more awkward to read back into Mma.

edited Dec 04 '13 at 07:44

answered Dec 04 '13 at 06:10

Ray Koopman

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Please see the OP's comment under @RiemannZeta answer. The nb has already been calculated. It's too late to change the code. – Dr. belisarius Dec 04 '13 at 11:44

How to collect expressions from cells created by Print?

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