Welcome to GDX2py’s documentation!

GDX2py is a Python package providing read and write support for GAMS GDX files using built-in data types list and dictionary.

API Reference

This page contains auto-generated API reference documentation 1.

gdx2py

Submodules

gdx2py.gams

Module contains classes for handling GAMS symbols

Module Contents
class gdx2py.gams.GAMSSet(keys: Sequence[tuple], domain: Sequence[str] = None, expl_text: str = '', assoc_texts: Sequence[str] = None)

Bases: gdx2py.gams._GAMSNDimSymbol

Class for GAMS Sets

elements

Set elements

Type

list

expl_text

Set explanatory text

Type

str

assoc_texts

Set element associated texts

Type

list

Constructor for GAMSSet

Parameters

  • keys – Sequence of tuples of strings for the keys

  • domain (optional) – Sequence of domain set names, use None for the universal set

  • expl_text (optional) – Explanatory text

  • assoc_texts (optional) – Set element associated texts

Raises

ValueError –

property elements(self)
property assoc_texts(self)
class gdx2py.gams.GAMSScalar(value: float, expl_text: str = '')

Bases: gdx2py.gams._GAMSSymbol

Class for GAMS Scalars (0-dimensional Parameters)

expl_text

Symbol explanatory text

Type

str

Class constructor

Parameters

  • name – Symbol name

  • value – Value

Raises

ValueError –

class gdx2py.gams.GAMSParameter(data: Mapping[tuple, float], domain: Sequence[str] = None, expl_text: str = '')

Bases: gdx2py.gams._GAMSNDimSymbol

Class for GAMS Parameters

domain

List of set names that make the domain of the symbol

Type

list

expl_text

Symbol explanatory text

Type

str

keys()

Return a view to the symbol’s keys

values()

Return a view to the symbol’s values

Constructor for GAMSParameter

Parameters

  • data – Dictionay of keys and values

  • domain (optional) – List of domain set names, use None for the universal set

  • expl_text (optional) – Explanatory text

Raises

ValueError –

keys(self)
values(self)
to_pandas(self)
gdx2py.gdxfile

Module for working with GAMS GDX files

Module Contents
gdx2py.gdxfile.GMS_DTYPES
gdx2py.gdxfile.GDX_DTYPE_TEXT = U254
gdx2py.gdxfile.GDX_DTYPE_LABEL = U63
gdx2py.gdxfile.GDX_DTYPE_NUM = f8
gdx2py.gdxfile.EPS_VALUE
gdx2py.gdxfile.SPECIAL_VALUES
gdx2py.gdxfile.GMS_USERINFO_SET_PARAMETER = 0
class gdx2py.gdxfile.GdxFile(filename: str, mode: str = 'r', gams_dir: str = None)

Bases: object

Class for working with a gdx file

Use subscripting (gdx_object[‘<symbolname>’]) to get/set a GAMS set or parameter symbol.

filename

Absolute filename

Type

str

Constructor for GdxFile

Parameters

  • filename – str

  • mode – File open mode: ‘r’ for reading, ‘w’ for writing, ‘w+’ for appending (replaces existing symbol)

  • gams_dir (optional) – Location of GAMS installation directory

Raises

  • RuntimeError – Unable to load gdx library, invalid mode

  • FileNotFoundError – Input file not found

  • ValueError – Unsupported mode

  • OSError – Unable to read/write file

  • Exception – Other errors

keys(self)
close(self)
static symrange(sym_count)

Package Contents

class gdx2py.GdxFile(filename: str, mode: str = 'r', gams_dir: str = None)

Bases: object

Class for working with a gdx file

Use subscripting (gdx_object[‘<symbolname>’]) to get/set a GAMS set or parameter symbol.

filename

Absolute filename

Type

str

Constructor for GdxFile

Parameters

  • filename – str

  • mode – File open mode: ‘r’ for reading, ‘w’ for writing, ‘w+’ for appending (replaces existing symbol)

  • gams_dir (optional) – Location of GAMS installation directory

Raises

  • RuntimeError – Unable to load gdx library, invalid mode

  • FileNotFoundError – Input file not found

  • ValueError – Unsupported mode

  • OSError – Unable to read/write file

  • Exception – Other errors

keys(self)
close(self)
static symrange(sym_count)
class gdx2py.GAMSSet(keys: Sequence[tuple], domain: Sequence[str] = None, expl_text: str = '', assoc_texts: Sequence[str] = None)

Bases: gdx2py.gams._GAMSNDimSymbol

Class for GAMS Sets

elements

Set elements

Type

list

expl_text

Set explanatory text

Type

str

assoc_texts

Set element associated texts

Type

list

Constructor for GAMSSet

Parameters

  • keys – Sequence of tuples of strings for the keys

  • domain (optional) – Sequence of domain set names, use None for the universal set

  • expl_text (optional) – Explanatory text

  • assoc_texts (optional) – Set element associated texts

Raises

ValueError –

property elements(self)
property assoc_texts(self)
class gdx2py.GAMSScalar(value: float, expl_text: str = '')

Bases: gdx2py.gams._GAMSSymbol

Class for GAMS Scalars (0-dimensional Parameters)

expl_text

Symbol explanatory text

Type

str

Class constructor

Parameters

  • name – Symbol name

  • value – Value

Raises

ValueError –

class gdx2py.GAMSParameter(data: Mapping[tuple, float], domain: Sequence[str] = None, expl_text: str = '')

Bases: gdx2py.gams._GAMSNDimSymbol

Class for GAMS Parameters

domain

List of set names that make the domain of the symbol

Type

list

expl_text

Symbol explanatory text

Type

str

keys()

Return a view to the symbol’s keys

values()

Return a view to the symbol’s values

Constructor for GAMSParameter

Parameters

  • data – Dictionay of keys and values

  • domain (optional) – List of domain set names, use None for the universal set

  • expl_text (optional) – Explanatory text

Raises

ValueError –

keys(self)
values(self)
to_pandas(self)
1

Created with sphinx-autoapi

Usage

GdxFile objects behave like dictionaries.

>>> from gdx2py import GdxFile, GAMSSet, GAMSScalar, GAMSParameter
>>> with GdxFile('/path/to/gdx/file.gdx', mode='w') as gdx:
>>>     gdx['set1'] = ['a', 'b', 'c']  # Write a simple set
>>>     set1 = gdx['set1']  # Read a symbol
>>>     # Write a 2-dimensional set
>>>     gdx['set2'] = [('a', 'foo'), ('b', 'bar'), ('c', 'baz')]
>>>     # Write a scalar with explanatory text
>>>     pi = GAMSScalar(3.14, expl_text="Value of pi")
>>>     gdx['pi'] = pi

GAMS symbol objects

The symbol returned is either a GAMSSet, GAMSParameter or GAMSScalar. You can convert them to Python built-ins.

>>> float(pi)
3.14
>>> list(set1)
['a', 'b', 'c']
>>> par = GAMSParameter({'a': 1, 'b': 2, 'c': 3, 'd': 4 })
>>> dict(par)
{'a': 1, 'b': 2, 'c': 3, 'd': 4 }

Symbol domains

GAMS sets and parameteres can also have a domain. Use the optional domain parameter to the constructor to define the domain.

>>> cats = GAMSSet(['jaguar', 'lion', 'tiger'], domain=['animals'])

The universal set (‘*’ in GAMS) means there is no specific domain. Use None for the universal set.

>>> set2d = GAMSSet([('a', 'foo'), ('b', 'bar'), ('c', 'baz')], domain=['abc', None])

Indices and tables