Install & Compatibility
Where this runs
tested against v2.2.0 · pip install
no network on importno background threads
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
muslpy 3.10–3.920 runs
installs and imports cleanly · install 0.0s · import 0.043s · 17.9MB
glibcpy 3.10–3.920 runs
installs and imports cleanly · install 1.6s · import 0.038s · 18MB
16MB installed
● package 16MB
Code
Verified usage
Verified import paths — ran on the pinned version, not inferred.
diff
✓ from datadiff import diff
✗ from data_diff import diff_tables
This `datadiff` library is for Python data structures. The `data-diff` library (with a hyphen) is a separate tool for database table comparisons and uses different import paths and functionalities.
This example demonstrates how to use `datadiff.diff` to compare two Python dictionaries, showing changes in values, lists, and new keys.
from datadiff import diff
a = dict(foo=1, bar=2, baz=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
b = dict(foo=1, bar=4, baz=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'changed', 11], qux='new')
result = diff(a, b)
print(result)
Debug
Known issues
gotchaThis `datadiff` library (no hyphen) is specifically for diffing Python data structures (dicts, lists, sets, strings). There is a similarly named but entirely different library, `data-diff` (with a hyphen), which focuses on diffing database tables. Ensure you are installing and importing the correct library for your use case to avoid confusion.fixVerify the PyPI package name (`datadiff` vs. `data-diff`) and import paths (`from datadiff import diff` vs. `from data_diff import connect_to_table`).
affects: All versions
gotchaWhile `datadiff` states compatibility with Python 2.6 through Python 3, using it in modern Python 3-only projects might encounter subtle compatibility issues or less optimized behavior compared to Python 3-native diffing tools. Its feature set might not leverage newer Python 3 language features.fixTest thoroughly in your specific Python 3 environment. For deep, custom object diffing, consider implementing `__eq__` and `__repr__` methods on your custom classes, or converting them to standard data structures before diffing.
affects: All versions, especially when migrating from Python 2 or mixing with modern Python 3 codebases.
Errors
Common errors & fixes
ModuleNotFoundError: No module named 'data_diff'
You have installed `datadiff` (for Python data structures) but are trying to import `data_diff` (with an underscore), which belongs to the database diffing tool `data-diff`.
fixIf you intend to compare Python data structures, use `from datadiff import diff`. If you intend to compare databases, run `pip install data-diff` and then import `from data_diff import connect_to_table, diff_tables`.
Diff output for custom objects is unhelpful (e.g., shows memory addresses or object representations without semantic differences).
`datadiff` is optimized for standard Python collections. For custom objects, it may fall back to default object comparison, which often relies on `id()` or `__repr__()` if `__eq__()` is not properly implemented.
fixFor meaningful diffs of custom objects, ensure your classes implement `__eq__` and `__repr__` methods, or convert your custom objects into standard Python dictionaries or lists before passing them to `datadiff.diff()`.
Upgrade
Version history
2.2.0latest on PyPI · released Aug 27, 2023
Audit
Dependencies
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