class documentation

class _FloatType(_NumericType, sqltypes.Float):

Known subclasses: sqlalchemy.dialects.mysql.types.DOUBLE, sqlalchemy.dialects.mysql.types.FLOAT, sqlalchemy.dialects.mysql.types.REAL

View In Hierarchy

Undocumented

Method __init__ Construct a Float.
Method __repr__ Undocumented
Instance Variable scale Undocumented

Inherited from _NumericType:

Instance Variable unsigned Undocumented
Instance Variable zerofill Undocumented

Inherited from Float:

Method result​_processor Return a conversion function for processing result row values.
Class Variable __visit​_name__ Undocumented
Instance Variable asdecimal Undocumented
Instance Variable decimal​_return​_scale Undocumented
Instance Variable precision Undocumented

Inherited from Numeric (via Float):

Method bind​_processor Return a conversion function for processing bind values.
Method get​_dbapi​_type Return the corresponding type object from the underlying DB-API, if any.
Method literal​_processor Return a conversion function for processing literal values that are to be rendered directly without using binds.
Class Variable ​_default​_decimal​_return​_scale Undocumented
Property ​_effective​_decimal​_return​_scale Undocumented
Property ​_expression​_adaptations Undocumented
Property python​_type Return the Python type object expected to be returned by instances of this type, if known.

Inherited from _LookupExpressionAdapter (via Float, Numeric):

Class ​Comparator Undocumented

Inherited from TypeEngine (via Float, Numeric):

Class ​Comparator Base class for custom comparison operations defined at the type level. See .TypeEngine.comparator_factory.
Method adapt Produce an "adapted" form of this type, given an "impl" class to work with.
Method as​_generic Return an instance of the generic type corresponding to this type using heuristic rule. The method may be overridden if this heuristic rule is not sufficient.
Method bind​_expression Given a bind value (i.e. a .BindParameter instance), return a SQL expression in its place.
Method coerce​_compared​_value Suggest a type for a 'coerced' Python value in an expression.
Method column​_expression Given a SELECT column expression, return a wrapping SQL expression.
Method compare​_against​_backend Compare this type against the given backend type.
Method compare​_values Compare two values for equality.
Method compile Produce a string-compiled form of this .TypeEngine.
Method dialect​_impl Return a dialect-specific implementation for this .TypeEngine.
Method evaluates​_none Return a copy of this type which has the .should_evaluate_none flag set to True.
Method with​_variant Produce a new type object that will utilize the given type when applied to the dialect of the given name.
Class Variable hashable Flag, if False, means values from this type aren't hashable.
Class Variable should​_evaluate​_none If True, the Python constant None is considered to be handled explicitly by this type.
Class Variable sort​_key​_function A sorting function that can be passed as the key to sorted.
Static Method ​_to​_instance Undocumented
Method __str__ Undocumented
Method ​_cached​_bind​_processor Return a dialect-specific bind processor for this type.
Method ​_cached​_custom​_processor Undocumented
Method ​_cached​_literal​_processor Return a dialect-specific literal processor for this type.
Method ​_cached​_result​_processor Return a dialect-specific result processor for this type.
Method ​_compare​_type​_affinity Undocumented
Method ​_default​_dialect Undocumented
Method ​_dialect​_info Return a dialect-specific registry which caches a dialect-specific implementation, bind processing function, and one or more result processing functions.
Method ​_gen​_dialect​_impl Undocumented
Method ​_resolve​_for​_literal adjust this type given a literal Python value that will be stored in a bound parameter.
Method ​_unwrapped​_dialect​_impl Return the 'unwrapped' dialect impl for this type.
Method copy Undocumented
Method copy​_value Undocumented
Class Variable ​_is​_array Undocumented
Class Variable ​_is​_table​_value Undocumented
Class Variable ​_is​_tuple​_type Undocumented
Class Variable ​_is​_type​_decorator Undocumented
Class Variable ​_isnull Undocumented
Class Variable ​_sqla​_type Undocumented
Property ​_generic​_type​_affinity Undocumented
Property ​_has​_bind​_expression memoized boolean, check if bind_expression is implemented.
Property ​_has​_column​_expression memoized boolean, check if column_expression is implemented.
Property ​_static​_cache​_key Undocumented
Property ​_type​_affinity Return a rudimental 'affinity' value expressing the general class of type.

Inherited from Traversible (via Float, Numeric, TypeEngine):

Method get​_children Return immediate child .visitors.Traversible elements of this .visitors.Traversible.
Method __class​_getitem__ Undocumented
def __init__(self, precision=None, scale=None, asdecimal=True, **kw):
Construct a Float.
Parameters
precisionthe numeric precision for use in DDL CREATE TABLE.
scaleUndocumented
asdecimalthe same flag as that of .Numeric, but defaults to False. Note that setting this flag to True results in floating point conversion.
**kwUndocumented
decimal​_return​_scale

Default scale to use when converting from floats to Python decimals. Floating point values will typically be much longer due to decimal inaccuracy, and most floating point database types don't have a notion of "scale", so by default the float type looks for the first ten decimal places when converting. Specifying this value will override that length. Note that the MySQL float types, which do include "scale", will use "scale" as the default for decimal_return_scale, if not otherwise specified.

New in version 0.9.0.
def __repr__(self):
scale =

Undocumented