Or: data = [d for d in [get_job_efficiency_dict(job_id) for job_id in job_ids] if d is not None]
or for job_id in job_ids: if (d := get_job_efficiency_dict(job_id)) is not None: data.append(d) Personally, I’d got with the latter in my own code. — Gerard Weatherby | Application Architect NMRbox | NAN | Department of Molecular Biology and Biophysics UConn Health 263 Farmington Avenue, Farmington, CT 06030-6406 uchc.edu On Aug 4, 2022, 2:52 PM -0400, MRAB <pyt...@mrabarnett.plus.com>, wrote: *** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. *** On 2022-08-04 12:51, Loris Bennett wrote: Hi, I am constructing a list of dictionaries via the following list comprehension: data = [get_job_efficiency_dict(job_id) for job_id in job_ids] However, get_job_efficiency_dict(job_id) uses 'subprocess.Popen' to run an external program and this can fail. In this case, the dict should just be omitted from 'data'. I can have 'get_job_efficiency_dict' return 'None' and then run filtered_data = list(filter(None, data)) but is there a more elegant way? I'm not sure how elegant it is, but: data = [result for job_id in job_ids if (result := get_job_efficiency_dict(job_id)) is not None] -- https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!iqxhYMoHcYQY1xohGCpafpBKZIUcGEV6Zj1-RLzOCF61TUXGr-8oh9HLuL-H8w4gxgDCypcOYOYkqNXLJxUIqhWd$ -- https://mail.python.org/mailman/listinfo/python-list