marshmallow-code/marshmallow

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A lightweight library for converting complex objects to and from simple Python datatypes.

Stars: 7.2k
Forks: 738
Open beginner issues: 0
Indexed issues: 117
Avg merge: 1d 23h
Merged PRs (30d): 7

Dominant language: Python
License: MIT
Last GitHub push: Sep 15, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted

Beginner friendly Everything

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117 open issues indexed

Object to pass to Nested as missing Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

marshmallow-code/marshmallow#1042 · 13 comments · 17 reactions · Opened Nov 7, 2018
fields.Nested should optionally pass the parent object to the Nested Schema Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

marshmallow-code/marshmallow#940 · 12 comments · 6 reactions · Opened Sep 7, 2018
fields.Boolean should accept only json booleans Open

feedback welcome

Difficulty 3/5 1-2 days Newbie friendliness 35/100

marshmallow-code/marshmallow#902 · 4 comments · 8 reactions · Opened Aug 3, 2018
How to report errors for container fields? Open

backwards incompat feedback welcome refactor

Difficulty 5/5 Over a week Newbie friendliness 20/100

marshmallow-code/marshmallow#879 · 11 comments · Opened Jul 11, 2018
Allow specifying output field when using `unknown=INCLUDE` Open

feedback welcome help wanted

Difficulty 4/5 3-5 days Newbie friendliness 35/100

marshmallow-code/marshmallow#853 · 3 comments · 4 reactions · Opened Jun 23, 2018
Passing extra kwargs with ValidationError Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

marshmallow-code/marshmallow#833 · 8 reactions · Opened Jun 6, 2018
Investigate Serialization Performance Open

marshmallow-code/marshmallow#805 · 27 comments · 3 reactions · 1 assignee · Opened May 14, 2018
Configuring only, exclude, load_only, and dump_only on fields.Nested() Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

marshmallow-code/marshmallow#802 · 2 comments · 1 reaction · Opened May 13, 2018
allow for overriding dump’s iteration behavior Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

marshmallow-code/marshmallow#798 · Opened May 8, 2018
RFC: Remove Nested(many=True) to keep only the List(Nested()) form Open

backwards incompat feedback welcome

Difficulty 5/5 Over a week Newbie friendliness 25/100

marshmallow-code/marshmallow#779 · 42 comments · 16 reactions · Opened Apr 19, 2018
Suggestion: Refactor builtin fields to expose validators for re-use Open

refactor

Difficulty 5/5 Over a week Newbie friendliness 35/100

marshmallow-code/marshmallow#760 · 1 comment · 2 reactions · Opened Mar 28, 2018
Add decorator syntax for method fields? Open

feedback welcome

Difficulty 5/5 Over a week Newbie friendliness 25/100

marshmallow-code/marshmallow#738 · 4 comments · Opened Feb 16, 2018
Incorrect Integer validation for Floats Open

Difficulty 2/5 1-3 hours Newbie friendliness 58/100

marshmallow-code/marshmallow#727 · 3 comments · 7 reactions · Opened Jan 24, 2018
Empty strings as None (revisited) Open

feedback welcome

Difficulty 5/5 Over a week Newbie friendliness 35/100

marshmallow-code/marshmallow#713 · 32 comments · 18 reactions · Opened Jan 2, 2018
Schema fields with dict attribute names return dict attributes when keys missing Open

feedback welcome needs review

Difficulty 5/5 Over a week Newbie friendliness 30/100

marshmallow-code/marshmallow#648 · 7 comments · Opened Jun 14, 2017
How is deserialization affected by only and partial? Open

docs

Difficulty 4/5 3-5 days Newbie friendliness 25/100

marshmallow-code/marshmallow#535 · 3 comments · Opened Sep 28, 2016
Can't json encode some validation errors, "unorderable types: str() < int()" Open

backwards incompat feedback welcome

Difficulty 2/5 1-3 hours Newbie friendliness 38/100

marshmallow-code/marshmallow#493 · 14 comments · Opened Jul 12, 2016

marshmallow-code/marshmallow

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