ImportError: cannot import name 'soft_unicode' from 'markupsafe'

How to fix ImportError: cannot import name 'soft_unicode' from 'markupsafe'

markupsafe 2.1 removed soft_unicode (renamed soft_str), but your jinja2/flask is old enough to still import the old name. Upgrade the stack: pip install -U flask jinja2 markupsafe. Quick unblock: pip install markupsafe==2.0.1, which still has soft_unicode.

The exact error

ImportError: cannot import name 'soft_unicode' from 'markupsafe'

Fix it

1. pip install -U flask jinja2 markupsafe Expected: modern mutually-compatible versions

2. Retry the import. Expected: works

3. Can not upgrade the app? pip install markupsafe==2.0.1 as a stopgap. Expected: old jinja2 finds soft_unicode again

When this applies

the traceback shows an old jinja2/flask importing soft_unicode from a new markupsafe

When this does NOT apply

your own code imports softunicode (just use softstr)

Versions

markupsafe >= 2.1 with jinja2 < 3.0 / flask < 2.0

Why it happens

markupsafe 2.1 did the py2-cleanup rename; old jinja2 (<3.0) still asked for the old name.

Edge cases

aws-sam-cli below 1.38.1 is another classic trigger; upgrade sam instead.

Asked about: ImportError: cannot import name 'softunicode' from 'markupsafe' (gh:koheron/koheron-sdk#648). The verified fix: markupsafe 2.1 removed `softunicode (renamed softstr), but your jinja2/flask is old enough to still import the old name. Upgrade the stack: pip install -U flask jinja2 markupsafe. Quick unblock: pip install markupsafe==2.0.1`, which still has softunicode. Full thread: https://github.com/koheron/koheron-sdk/issues/648