PYSON

PYSON#

PYSON is the Python Statement and Object Notation.

There is also a more practical introduction into PYSON statements.

class trytond.pyson.PYSON#: Base class of any PYSON statement. It is never used directly.

Instance methods:

PYSON.pyson()#: Return the internal dictionary representation of the statement.

PYSON.types()#: Return a set of all possible types which the statement can become when evaluated.

Class methods:

classmethod PYSON.eval(dct, context)#

Return the evaluation of the statement given in dct within the context.

dct contains a dictionary which is the internal representation of a PYSON statement.

context contains a dictionary with contextual values.

Encoder and Decoder#

class trytond.pyson.PYSONEncoder#: Encoder for PYSON statements into string representations.

Instance methods:

PYSONEncoder.encode(object)#

Return a string representation of a given PYSON statement.

object contains a PYSON statement.

class trytond.pyson.PYSONDecoder([context[, noeval]])#: Decoder for string into the evaluated or not PYSON statement.

Instance methods:

PYSONDecoder.decode(object)#

Return a PYSON statement evaluated or not of a given string.

object contains a string.

Statements#

The following classes can be used as PYSON statement:

Eval #

class trytond.pyson.Eval(value[, default])#

Represent the PYSON statement for evaluations.

When evaluated, it returns the value of the statement named by value, if defined in the evaluation context, otherwise the default value (empty string by default).

Note

The default value determines the type of the statement.

Note

If the value includes dots the value will be dereferenced. For example:

Eval('_parent_sale.number')

The number value of the _parent_sale key of the evaluation context will be returned.

Not #

class trytond.pyson.Not(value)#

Represent the PYSON statement for logical negations.

When evaluated, returns the boolean negation of the value of the statement named by value, if defined in the evaluation context. Returns an instance of itself.

Bool #

class trytond.pyson.Bool(value)#

Represent the PYSON statement for boolean evaluations.

Returns the boolean representation of the value of the statement named by value.

And #

class trytond.pyson.And(\*statements)#

Represent the PYSON statement for logical and operations.

Returns the result of the logical conjunction of two or more values named by the statements in the statements tuple.

Or #

class trytond.pyson.Or(\*statements)#

Represent the PYSON statement for logical or operations.

Returns the result of the logical disjunction of two or more values named by the statements in the statements tuple.

Equal #

class trytond.pyson.Equal(statement1, statement2)#

Represent the PYSON statement for equation comparisons.

Returns True when a value of a statement named by statement1 and the value of a statement named by statement2 are equal, otherwise returns False.

Greater #

class trytond.pyson.Greater(statement1, statement2[, equal])#

Represent the PYSON statement for greater-than comparisons.

Returns True when the value of the statement named by statement1 is strictly greater than the value of the statement named by statement2, otherwise returns false. Is the value of the variable named by equal is True, then returns also True when both values of statements named by statement1 and statement2 are equal. In this case Greater works as a greater-than or equal operator.

Note

None value is replaced by 0 for the comparison.

Less #

class trytond.pyson.Less(statement1, statement2[, equal])#

Represent the PYSON statement for less-than comparisons.

Returns True when the value of the statement named by statement1 is strictly less than the value of the statement named by statement2, otherwise returns False. Is the value of the variable named equal is true, then returns also true when both values of the statements named by statement1 and statement2 are equal. In this case Less works as a less-than or equal operator.

Note

None value is replaced by 0 for the comparison.

If #

class trytond.pyson.If(condition, then_statement, else_statement)#

Represent the PYSON statement for conditional flow control operations.

Returns the value of the statement named by then_statement when the value of the statement named by condition evaluates true. Otherwise returns the value of the statement named by else_statement.

Get #

class trytond.pyson.Get(obj, key[, default])#

Represent the PYSON statement for dictionary look-up operations and evaluation.

Look up and returns the value of a key named by key in an object named by obj if defined. Otherwise returns the value of the variable named by default.

In #

class trytond.pyson.In(key, obj)#

Represent the PYSON statement for look-up dictionary or integer objects.

Returns true when a list (or dictionary) object named by obj contains the value of the variable (or key) named by key. Otherwise returns false.

Date #

class trytond.pyson.Date([year[, month[, day[, delta_years[, delta_month[, delta_days[, start]]]]]]])#

Represent the PYSON statement for date related conversions and basic calculations.

Returns a date object which represents the values of arguments named by the variables explained below. Missing values of arguments named by year or month or day take their defaults from start or the actual date. When values of arguments named by delta_* are given, they are added to the values of the appropriate arguments in a date and time preserving manner.

Arguments:

year: A PYSON statement of type int or long.
month: A PYSON statement of type int or long.
day: A PYSON statement of type int or long.
delta_years: A PYSON statement of type int or long.
delta_month: A PYSON statement of type int or long.
delta_days: A PYSON statement of type int or long.
start: A PYSON statement of type date.

DateTime #

class trytond.pyson.DateTime([year[, month[, day[, hour[, minute[, second[, microsecond[, delta_years[, delta_months[, delta_days[, delta_hours[, delta_minutes[, delta_seconds[, delta_microseconds[, start]]]]]]]]]]]]]]])#

Represent the PYSON statement for date and time related conversions and calculations.

Returns a date time object which represents the values of variables named by the arguments explained below. Missing values of arguments named by year, month, day, hour, minute, second, microseconds take their defaults from start or the actual date and time in UTC. When values of arguments named by delta_* are given, these are added to the appropriate attributes in a date and time preserving manner.

Arguments:

year: A PYSON statement of type int or long.
month: A PYSON statement of type int or long.
day: A PYSON statement of type int or long.
hour: A PYSON statement of type int or long.
minute: A PYSON statement of type int or long.
second: A PYSON statement of type int or long.
microsecond: A PYSON statement of type int or long.
delta_years: A PYSON statement of type int or long.
delta_month: A PYSON statement of type int or long.
delta_days: A PYSON statement of type int or long.
delta_hours: A PYSON statement of type int or long.
delta_minutes: A PYSON statement of type int or long.
delta_seconds: A PYSON statement of type int or long.
delta_microseconds: A PYSON statement of type int or long.
start: A PYSON statement of type datetime.

Len #

class trytond.pyson.Len(value)#

Represent the PYSON statement for length of a dictionary, list or string.

Returns the number of items in value.

Id #

class trytond.pyson.Id(module, fs_id)#

Represent the PYSON statement for filesystem id evaluations.

When converted into the internal dictionary, it returns the database id stored in ir.model.data.

PYSON

Contents

PYSON#

Encoder and Decoder#

Statements#