pip install asn1crypto==1.4.0

Fast ASN.1 parser and serializer with definitions for private keys, public keys, certificates, CRL, OCSP, CMS, PKCS#3, PKCS#7, PKCS#8, PKCS#12, PKCS#5, X.509 and TSP

Source
Among top 100 packages on PyPI.
Over 74.5M downloads in the last 90 days.

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Based on how often these packages appear together in public requirements.txt files on GitHub.

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Version usage of asn1crypto

Proportion of downloaded versions in the last 3 months (only versions over 1%).

1.4.0

90.39%

0.24.0

7.63%

1.3.0

1.11%