GC and security

[Les Schaffer]

i am working on a python application that uses encryption as part of its
security features. so then at some point someone has to enter a
passphrase into the system and passed into a decryption functions (we
are using gpg via subprocess).

so i am curious. so long as i drop all reference to the passphrase
string(s), eventually it gets garbage collected and the memory recycled.
so "before long" the phrase is gone from memory.

is there a best practice way to do this?

thanks

Les Schaffer