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POLoad module from string in python
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copied!<p>I have some code in the form of a string and would like to make a module out of it without writing to disk.</p> <p>When I try using imp and a StringIO object to do this, I get:</p> <pre><code>>>> imp.load_source('my_module', '', StringIO('print "hello world"')) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: load_source() argument 3 must be file, not instance >>> imp.load_module('my_module', StringIO('print "hello world"'), '', ('', '', 0)) Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: load_module arg#2 should be a file or None </code></pre> <p>How can I create the module without having an actual file? Alternatively, how can I wrap a StringIO in a file without writing to disk?</p> <p><strong>UPDATE:</strong></p> <p>NOTE: This issue is also a problem in python3.</p> <p>The code I'm trying to load is only partially trusted. I've gone through it with ast and determined that it doesn't import anything or do anything I don't like, but I don't trust it enough to run it when I have local variables running around that could get modified, and I don't trust my own code to stay out of the way of the code I'm trying to import.</p> <p>I created an empty module that only contains the following:</p> <pre><code>def load(code): # Delete all local variables globals()['code'] = code del locals()['code'] # Run the code exec(globals()['code']) # Delete any global variables we've added del globals()['load'] del globals()['code'] # Copy k so we can use it if 'k' in locals(): globals()['k'] = locals()['k'] del locals()['k'] # Copy the rest of the variables for k in locals().keys(): globals()[k] = locals()[k] </code></pre> <p>Then you can import <code>mymodule</code> and call <code>mymodule.load(code)</code>. This works for me because I've ensured that the code I'm loading does not use <code>globals</code>. Also, the <code>global</code> keyword is only a parser directive and can't refer to anything outside of the exec.</p> <p>This really is way too much work to import the module without writing to disk, but if you ever want to do this, I believe it's the best way.</p>

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