at.load.file_input

Generic text parsers for conversion of lattices in different formats to AT.

Functions

ignore_class(classname, baseclass[, module])	Generate a class for ignored elements.
skip_class(classname, baseclass[, module])	Generate a class for skipped elements.

Classes

AnyDescr(*args, **kwargs)	Base class for source object descriptors.
BaseParser(env[, strict, verbose, always_force])	Generic file parser.
DictNoDot(*args[, verbose])
ElementDescr(*args[, origin])	Simple representation of an element as a dict.
LowerCaseParser(env[, strict, verbose, ...])	Case independent parser.
SequenceDescr(*args, **kwargs)	Simple representation of a sequence of elements as a list.
UnorderedParser(env, **kwargs)	Parser allowing definitions in any order.
UpperCaseParser(env[, strict, verbose, ...])	Case independent parser.

class AnyDescr(*args, **kwargs)

Bases: object

Base class for source object descriptors.

classmethod argparser(parser, argcount, argstr)

Specialised argument parser.

expand(parser)

Iterator on the generated AT elements.

inverted(copy=False)

Return a reversed element or line.

update(*args, **kwargs)

bool_attr: ClassVar[set[str]] = {}

list of names of bool attributes

pos_args: ClassVar[tuple[str, ...]] = ()

list of names of positional arguments

str_attr: ClassVar[set[str]] = {}

list of names of str attributes

class BaseParser(env, strict=True, verbose=False, always_force=True, **kwargs)

Bases: DictNoDot, StrParser

Generic file parser.

Analyses files with the following MAD-like format:

variable = value

label : command [,attribute=value] [,attribute=value]...

The parser builds a database of all the defined objects

Parameters:

• env (dict[str, Any]) – global namespace used for evaluating commands

• verbose (bool) – If True, print detail on the processing

• strict (bool) – If False, assign 0 to undefined variables

• **kwargs – dict initialiser.

clear()

Clear the database: remove all parameters and objects.

evaluate(expr)

Evaluate the right side of an expression.

Parameters:

expr (str) – expression to evaluate

Returns:

value – evaluated expression

expand(key)

iterator over AT objects generated by a source object.

lattice(use='ring', **kwargs)

Create a lattice from the selected sequence.

Parameters:

use – Name of the sequence or line containing the desired lattice. Default: ring

Keyword Arguments:

• name (str) – Name of the lattice. Default: sequence name.

• particle (Particle) – Circulating particle. Default: Particle(“relativistic”)

• energy (float) – Energy of the lattice [eV]. Default: 1.0 GeV

• periodicity (int) – Number of periods. Default: 1

• * – All other keywords will be set as Lattice attributes

parse_files(*filenames, final=True, prolog=None, epilog=None, **kwargs)

Process files and fill the database.

Parameters:

• *filenames (str | Path) – Files to process

• final (bool) – If True, signals that the undefined variables may be set to the default value

• prolog (None | int | Callable[[...], None])

• epilog (Callable[[...], None] | None)

• **kwargs – Initial variable definitions

parse_lines(lines, *, final=True, **kwargs)

Process input lines and fill the database.

Parameters:

• lines (Iterable[str]) – Iterable of input lines

• final (bool) – If True, signals that the undefined variables may be set to the default value

• **kwargs – Initial variable definitions

property ignored

Set of ignored commands.

in_file: list[str]

property missing

Set of missing definitions

postponed: list[tuple]

property sequences

List of available sequences or lines.

class DictNoDot(*args, verbose=False, **kwargs)

Bases: dict

get(key, *args)

Return the value for key if key is in the dictionary, else default.

class ElementDescr(*args, origin=None, **kwargs)

Bases: AnyDescr, dict

Simple representation of an element as a dict.

classmethod from_at(kwargs)

static attr_format(value)

static meval(params)

Evaluation of superfluous parameters.

expand(parser)

Iterator on the generated AT elements.

to_at(*args, **params)

Generate the AT element. Must be overloaded for each specific element.

array_fmt = {40: 123, 41: 125, 91: 123, 93: 125}

at2mad: ClassVar[dict[str, str]] = {'Length': 'L'}

bool_fmt: ClassVar[dict[bool, str]] = {False: 'False', True: 'True'}

property length: float

Element length.

class LowerCaseParser(env, strict=True, verbose=False, always_force=True, **kwargs)

Bases: BaseParser

Case independent parser.

Parameters:

• env (dict[str, Any]) – global namespace used for evaluating commands

• verbose (bool) – If True, print detail on the processing

• strict (bool) – If False, assign 0 to undefined variables

• **kwargs – dict initialiser.

class SequenceDescr(*args, **kwargs)

Bases: AnyDescr, list

Simple representation of a sequence of elements as a list.

property length: float

class UnorderedParser(env, **kwargs)

Bases: BaseParser

Parser allowing definitions in any order.

This is done by storing the failed statements in a queue and iteratively trying to execute them after all input statements have been processed, until the number of failures is constant (hopefully zero)

Parameters:

• env (dict[str, Any]) – global namespace used for evaluating commands

• verbose – If True, print detail on the processing

• strict – If False, assign 0 to undefined variables

• **kwargs – dict initialiser.

class UpperCaseParser(env, strict=True, verbose=False, always_force=True, **kwargs)

Bases: BaseParser

Case independent parser.

Parameters:

• env (dict[str, Any]) – global namespace used for evaluating commands

• verbose (bool) – If True, print detail on the processing

• strict (bool) – If False, assign 0 to undefined variables

• **kwargs – dict initialiser.

ignore_class(classname, baseclass, module=None, **kwargs)

Generate a class for ignored elements.

The element generates an AT Drift or Marker element depending on its length.

Parameters:

• classname (str) – Name of the generated class

• baseclass (type[ElementDescr]) – Base class, must be a subclass of ElementDescr

• module (str | None) – Name of the module where the class is defined. If None, use the module of the base class.

• **kwargs – dictionary of additional attributes and methods. See type().

Returns:

cls – Element class, converted to Marker or Drift when generating AT elements

skip_class(classname, baseclass, module=None, **kwargs)

Generate a class for skipped elements.

No AT element is generated for these elements.

Parameters:

• classname (str) – Name of the generated class

• baseclass (type[ElementDescr]) – Base class, must be a subclass of ElementDescr

• module (str | None) – Name of the module where the class is defined. If None, use the module of the base class.

• **kwargs – dictionary of additional attributes and methods. See type().

Returns:

cls – Element class, skipped when generating AT elements