Update retrieving-your-data.rst
Merge pull request #1097 from aavrug/patch-11

Update retrieving-your-data.rst
Update data-validation.rst
Merge pull request #1098 from aavrug/patch-12

Update data-validation.rst
Correction d'une petite faute
Merge pull request #1099 from superdupont/patch-1

Correction d'une petite faute
Update hash.rst to have entry for apply()

apply() is listed at the top of the doc, but there is no entry for it below.
Merge pull request #1100 from sophistry/patch-1

Update hash.rst to have entry for apply()
Update caching.rst

In a cache you can save numeric values and 0 is a valid return value so a strict egality sould be tested with false
Merge pull request #1101 from superdupont/patch-2

Update caching.rst