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POPython: switching from optparse to argparse
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copied!<p>After switching from optparse to argparse - I'm experiencing strange errors. Argparse parse args only if leave no space:</p> <pre><code>myScript.py -oOpt </code></pre> <p>or put an equal sign:</p> <pre><code>myScript.py -o=Opt </code></pre> <p>and it doesn't work the normal way:</p> <pre><code>myScript.py -o Opt </code></pre> <p>Here's my argparse initialization:</p> <pre><code>#!/usr/bin/env python # to get description use the -h flag import argparse, os, sys # ====================== # Python2.7 is expected: if sys.version_info[0] != 2 or sys.version_info[1] < 7: sys.exit('This program needs Python2.7+') # ========== # preambule: desc = """Enter dirs in the current dir and makes gro out of state.cpt there.""" # parser = argparse.ArgumentParser() parser = argparse.ArgumentParser(description=desc, version='2.3', formatter_class=argparse.ArgumentDefaultsHelpFormatter) parser.add_argument('-w', '--workWith', help = 'to specify a Gromacs exec suffix', dest = 'wW', action = 'store', default = '-4.5.5-single', ) parser.add_argument('-g', '--gro', help = '.gro postfix: <nameOfTheDir><postfix>.gro', dest = 'myGroPostfix', action = 'store', default = "_membrane", ) parser.add_argument('-H', '--here', help = 'toggles - single (current) dir behaviour (the output will be state.gro)', dest = 'Here', action = 'store_true', ) parser.add_argument('-D', '--dirs', help = 'include these dirs (python\'s rgxp in SINGLE quotes), defaults to \'\'', dest = 'inclDirs', action = 'store', default = '', ) args = parser.parse_args() print args.wW </code></pre> <p><strong>Edit</strong>:</p> <p>Even more:</p> <pre><code> gmx_bk-simulate-mems.py -j bk-runs-mpi.bash -p 1 -w="-4.5.5-double_non-parallel_gcc" 2&> ../`date +%Y-%b-%d-%H%M%S`.log & </code></pre> <p>gives:</p> <pre><code> gmx_bk-simulate-mems.py: error: unrecognized arguments: 2 </code></pre> <p>it looks like <code>argparse</code> treats <code>2&></code> as option (or <code>2&></code> and <code>../date +%Y-%b-%d-%H%M%S.log</code> as options)!</p> <p><strong>Edit 2</strong>:</p> <p>So to summarize: </p> <ul> <li><p>For <code>argparse</code> - <code>"-4.5.5-double_non-parallel_gcc"</code> is a bad option name - and that's why it is required to write is as <code>-w="-4.5.5-double_non-parallel_gcc"</code>. For <code>optparse</code> and <code>bash</code> (!) this is fine. <code>bash</code> even gives an error at <code>-w="-4.5.5-double_non-parallel_gcc"</code> - it thinks that the arg is <code>="-4.5.5-double_non-parallel_gcc"</code> (!);</p></li> <li><p>There's no such thing as <code>2&></code>. <code>2></code> should might be used and it gives no errors;</p></li> <li><p>This is <code>shell</code> who splits the line into args, not <code>python</code>;</p></li> <li><p><code>argparse</code> is much better than <code>optparse</code>.</p></li> </ul>

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