Avoid module level sympy yet another time #5576
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Just as has been demonstrated many times in the past we should not be importing sympy at the module level. In Qiskit#5358 another import was added and was immediately flagged as an import speed regression [1]. Sympy is a very heavy dependency and is slow to import (and slow to run too). Adding a sympy import to the module level makes and is honestly a dependency we should be reluctant to add anywhere because it becomes the primary bottleneck whenever it is used. This commit removes the top level sympy import and moves to be a runtime import in the single method that uses sympy. Just as it was done in Qiskit#5416, Qiskit#5149, Qiskit#4385, and Qiskit#3156 before. Fixes Qiskit#5575 [1] https://qiskit.github.io/qiskit/#import.QiskitImport.time_qiskit_import?commits=300e9507
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kdk
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mtreinish
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This commit adds a new script that is run in CI to find whether slow optional imports are in the default qiskit import path. We've recently had several instances of PRs being pushed that added sympy to the default import path which makes the overall qiskit import significantly slower (see Qiskit#5576 for the most recent occurrence), this script will catch those siutations and report the error.
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#5582) * Add script to verify slow optional imports aren't used in default path This commit adds a new script that is run in CI to find whether slow optional imports are in the default qiskit import path. We've recently had several instances of PRs being pushed that added sympy to the default import path which makes the overall qiskit import significantly slower (see #5576 for the most recent occurrence), this script will catch those siutations and report the error. * Use virtualenv in CI for running new script The azure ci env was using system python instead of the venv where qiskit-terra was installed for running the new script. This was causing an error because to work the script imports qiskit to verify nothing slow is getting imported. This commit fixes this by explicitly using the venv python instead of the default system python to execute the script. * Add script to makefile too Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
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Summary
Just as has been demonstrated many times in the past we should not be
importing sympy at the module level. In #5358 another import was added
and was immediately flagged as an import speed regression [1]. Sympy is
a very heavy dependency and is slow to import (and slow to run too).
Adding a sympy import to the module level makes and is honestly a
dependency we should be reluctant to add anywhere because it becomes
the primary bottleneck whenever it is used. This commit removes the top
level sympy import and moves to be a runtime import in the single method
that uses sympy. Just as it was done in #5416, #5149, #4385, and #3156
before.
Details and comments
Fixes #5575
[1] https://qiskit.github.io/qiskit/#import.QiskitImport.time_qiskit_import?commits=300e9507