API Documentation¶
tinydb.database
¶
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class
tinydb.database.
TinyDB
(*args, **kwargs)¶ The main class of TinyDB.
Gives access to the database, provides methods to insert/search/remove and getting tables.
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DEFAULT_STORAGE
¶ alias of
JSONStorage
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__getattr__
(name)¶ Forward all unknown attribute calls to the underlying standard table.
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__init__
(*args, **kwargs)¶ Create a new instance of TinyDB.
All arguments and keyword arguments will be passed to the underlying storage class (default:
JSONStorage
).Parameters: storage – The class of the storage to use. Will be initialized with args
andkwargs
.
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__iter__
()¶ Iter over all elements from default table.
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__len__
()¶ Get the total number of elements in the default table.
>>> db = TinyDB('db.json') >>> len(db) 0
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close
()¶ Close the database.
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purge_table
(name)¶ Purge a specific table from the database. CANNOT BE REVERSED!
Parameters: name (str) – The name of the table.
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purge_tables
()¶ Purge all tables from the database. CANNOT BE REVERSED!
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table
(name='_default', **options)¶ Get access to a specific table.
Creates a new table, if it hasn’t been created before, otherwise it returns the cached
Table
object.Parameters: - name (str) – The name of the table.
- cache_size – How many query results to cache.
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table_class
¶ alias of
Table
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tables
()¶ Get the names of all tables in the database.
Returns: a set of table names Return type: set[str]
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class
tinydb.database.
Table
(storage, cache_size=10)¶ Represents a single TinyDB Table.
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__init__
(storage, cache_size=10)¶ Get access to a table.
Parameters: - storage (StorageProxyus) – Access to the storage
- cache_size – Maximum size of query cache.
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__iter__
()¶ Iter over all elements stored in the table.
Returns: an iterator over all elements. Return type: listiterator[Element]
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__len__
()¶ Get the total number of elements in the table.
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all
()¶ Get all elements stored in the table.
Returns: a list with all elements. Return type: list[Element]
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clear_cache
()¶ Clear the query cache.
A simple helper that clears the internal query cache.
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contains
(cond=None, eids=None)¶ Check wether the database contains an element matching a condition or an ID.
If
eids
is set, it checks if the db contains an element with one of the specified.Parameters: - cond (Query) – the condition use
- eids – the element IDs to look for
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get
(cond=None, eid=None)¶ Get exactly one element specified by a query or and ID.
Returns
None
if the element doesn’t existParameters: - cond (Query) – the condition to check against
- eid – the element’s ID
Returns: the element or None
Return type: Element | None
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insert
(element)¶ Insert a new element into the table.
Parameters: element – the element to insert Returns: the inserted element’s ID
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insert_multiple
(elements)¶ Insert multiple elements into the table.
Parameters: elements – a list of elements to insert Returns: a list containing the inserted elements’ IDs
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process_elements
(func, cond=None, eids=None)¶ Helper function for processing all elements specified by condition or IDs.
A repeating pattern in TinyDB is to run some code on all elements that match a condition or are specified by their ID. This is implemented in this function. The function passed as
func
has to be a callable. It’s first argument will be the data currently in the database. It’s second argument is the element ID of the currently processed element.Parameters: - func – the function to execute on every included element. first argument: all data second argument: the current eid
- cond – elements to use, or
- eids – elements to use
Returns: the element IDs that were affected during processed
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purge
()¶ Purge the table by removing all elements.
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remove
(cond=None, eids=None)¶ Remove all matching elements.
Parameters: - cond (query) – the condition to check against
- eids (list) – a list of element IDs
Returns: a list containing the removed element’s ID
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search
(cond)¶ Search for all elements matching a ‘where’ cond.
Parameters: cond (Query) – the condition to check against Returns: list of matching elements Return type: list[Element]
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update
(fields, cond=None, eids=None)¶ Update all matching elements to have a given set of fields.
Parameters: - fields (dict | dict -> None) – the fields that the matching elements will have or a method that will update the elements
- cond (query) – which elements to update
- eids (list) – a list of element IDs
Returns: a list containing the updated element’s ID
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tinydb.queries
¶
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class
tinydb.queries.
Query
¶ TinyDB Queries.
Allows to build queries for TinyDB databases. There are two main ways of using queries:
- ORM-like usage:
>>> User = Query() >>> db.search(User.name == 'John Doe') >>> db.search(User['logged-in'] == True)
- Classical usage:
>>> db.search(where('value') == True)
Note that
where(...)
is a shorthand forQuery(...)
allowing for a more fluent syntax.Besides the methods documented here you can combine queries using the binary AND and OR operators:
>>> db.search(where('field1').exists() & where('field2') == 5) # Binary AND >>> db.search(where('field1').exists() | where('field2') == 5) # Binary OR
Queries are executed by calling the resulting object. They expect to get the element to test as the first argument and return
True
orFalse
depending on whether the elements matches the query or not.-
__eq__
(rhs)¶ Test a dict value for equality.
>>> Query().f1 == 42
Parameters: rhs – The value to compare against
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__ge__
(rhs)¶ Test a dict value for being greater than or equal to another value.
>>> Query().f1 >= 42
Parameters: rhs – The value to compare against
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__gt__
(rhs)¶ Test a dict value for being greater than another value.
>>> Query().f1 > 42
Parameters: rhs – The value to compare against
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__le__
(rhs)¶ Test a dict value for being lower than or equal to another value.
>>> where('f1') <= 42
Parameters: rhs – The value to compare against
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__lt__
(rhs)¶ Test a dict value for being lower than another value.
>>> Query().f1 < 42
Parameters: rhs – The value to compare against
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__ne__
(rhs)¶ Test a dict value for inequality.
>>> Query().f1 != 42
Parameters: rhs – The value to compare against
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all
(cond)¶ Checks if a condition is met by any element in a list, where a condition can also be a sequence (e.g. list).
>>> Query().f1.all(Query().f2 == 1)
Matches:
{'f1': [{'f2': 1}, {'f2': 1}]}
>>> Query().f1.all([1, 2, 3]) # Match f1 that contains any element from [1, 2, 3]
Matches:
{'f1': [1, 2, 3, 4, 5]}
Parameters: cond – Either a query that all elements have to match or a list which has to be contained in the tested element.
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any
(cond)¶ Checks if a condition is met by any element in a list, where a condition can also be a sequence (e.g. list).
>>> Query().f1.any(Query().f2 == 1)
Matches:
{'f1': [{'f2': 1}, {'f2': 0}]}
>>> Query().f1.any([1, 2, 3]) # Match f1 that contains any element from [1, 2, 3]
Matches:
{'f1': [1, 2]} {'f1': [3, 4, 5]}
param cond: Either a query that at least one element has to match or a list of which at least one element has to be contained in the tested element.
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exists
()¶ Test for a dict where a provided key exists.
>>> Query().f1.exists() >= 42
Parameters: rhs – The value to compare against
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matches
(regex)¶ Run a regex test against a dict value (whole string has to match).
>>> Query().f1.matches(r'^\w+$')
Parameters: regex – The regular expression to use for matching
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search
(regex)¶ Run a regex test against a dict value (only substring string has to match).
>>> Query().f1.search(r'^\w+$')
Parameters: regex – The regular expression to use for matching
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test
(func, *args)¶ Run a user-defined test function against a dict value.
>>> def test_func(val): ... return val == 42 ... >>> Query().f1.test(test_func)
Parameters: - func – The function to call, passing the dict as the first argument
- args – Additional arguments to pass to the test function
tinydb.storage
¶
Contains the base class
for storages and
implementations.
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class
tinydb.storages.
Storage
¶ The abstract base class for all Storages.
A Storage (de)serializes the current state of the database and stores it in some place (memory, file on disk, ...).
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read
()¶ Read the last stored state.
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write
(data)¶ Write the current state of the database to the storage.
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close
()¶ Optional: Close open file handles, etc.
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tinydb.middlewares
¶
Contains the base class
for
middlewares and implementations.
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class
tinydb.middlewares.
Middleware
¶ The base class for all Middlewares.
Middlewares hook into the read/write process of TinyDB allowing you to extend the behaviour by adding caching, logging, ...
If
read()
orwrite()
are not overloaded, they will be forwarded directly to the storage instance.-
read
()¶ Read the last stored state.
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write
(data)¶ Write the current state of the database to the storage.
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close
()¶ Optional: Close open file handles, etc.
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class
tinydb.middlewares.
CachingMiddleware
(storage_cls=<class 'tinydb.storages.JSONStorage'>)¶ Add some caching to TinyDB.
This Middleware aims to improve the performance of TinyDB by writing only the last DB state every
WRITE_CACHE_SIZE
time and reading always from cache.-
flush
()¶ Flush all unwritten data to disk.
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