# `pydot` changelog
# SPDX-License-Identifier: MIT
# SPDX-FileCopyrightText: pydot contributors

Pydot versions since 1.4.2 adhere to [PEP 440-style semantic versioning]
(https://www.python.org/dev/peps/pep-0440/#semantic-versioning).


4.0.1 (2025-06-17)
------------------

Fixed:
- Updated pyparsing to `>=3.1.0`. Required for pydot to function correctly. (#477)
- Parser: Fixed 'strict' handling. (#480)
  The parser wasn't capturing the 'strict' keyword when parsing dot data. Now it does.
- Parser: Support backslash continuation in quoted IDs. (#487)
- Parser: Support +-concatenated quoted strings. (#490)


4.0.0 (2025-05-04)
------------------

Added:
- Added initial type annotations. (#430)
  There are still a lot of `Any`s, but Pydot now officially supports type annotations.
- Added (fixed) complex edge parsing. (#467)
  The parser now supports edges that contain subgraph endpoints.

Changed:
- Simplify `Common.get_top_graph_type` with a default. (#437)
- Define parser elements in a separate `GraphParser` class. (#464)
  It's a user-transparent change, but now it's easier to debug, test, and modify the parser.
  See the related Pull Request for more information.
- Improve return values and typing of setters and getters. (#470)

Fixed:
- Avoid subprocess window creation within `call_graphviz` on Windows. (#431)
- Removed a blank line inserted after subgraphs in the `to_string()` output. (#434)
- Fixed the issue where the parser breaks off lines at hash symbol following a HTML tag (#451)

Removed:
- Removed old, unused `Common.__get_attribute__`. (#426)


3.0.4 (2025-01-05)
------------------

- Fixed capitalized keywords in labels being unquoted. (#449, #450)


3.0.3 (2024-11-30)
------------------

- Fixed numeric quoting behavior. (#439)


3.0.2 (2024-09-25)
------------------

Added:
- All `to_string()` methods now accept an `indent` keyword argument, which can be
  either a number or a string. `indentation=4` will indent each level of the 
  output with four spaces. `indentation="  "` will indent each level by that many 
  spaces. Other whitespace is also valid, e.g. indent="\t" for tab indents. (#359)

Changed:
- Fixed quoting of identifiers with dots. (#419)
- Fixed quoting of leading-numeral strings (strings starting with a number). (#411)
- Fixed pickling/copying of Dot objects. (#403)
- Improved handling of temporary files. Temporary files will be cleaned up in
  all cases, even when exceptions are raised or things exit unexpectedly. (#394)
- From now on, the license files will be included in the distributed 
  release as expected. (#392)


3.0.1 (2024-07-16)
------------------

This is a bugfix release to correct a critical error introduced in 3.0.0.

Changed:
- Fix quoting in `Edge.to_string()`. (#384)


3.0.0 (2024-07-15)
------------------

Removed:
- Breaking change: support for Python 3.7 dropped totally (#371).
  It was already dropped, but now it's official.
- Breaking change (but for nobody): Invalid syntax removed (#377).
  Removed syntax rules that were never implemented in graphviz's own parser.
- Attribute sorting removed (#361).
  Pydot will preserve the original order of attributes as defined.
- Breaking change: Remove `.create_attribute_methods()` from classes (#318).
  Setters and getters for attributes are now added to class definitions
  by calls to `pydot.core.__generate_attribute_methods()` immediately
  after the class is defined, for better compatibility with type-checking
  and introspection.

Changed:
- Internal storage and lookup of identifiers (names) improved (#363).
  Pydot now always stores values as they were originally input, and only performs
  quoting on output.
  Previously, when a graph element was created with a name that contained a space
  or otherwise required quoting, the quotes would be added immediately, making it
  more difficult to retrieve the element using the `.get_*()` lookup methods.
  If a name requiring quotes was later set using `.set_name()`, no quotes would be
  added, causing the graph definition to become invalid.
  (Thanks to @tusharsadhwani for initially pointing out the name-quoting issues.)
- Quoting for attribute values fixed (#320).
  Attribute values containing comma-separated strings will now be quoted correctly.

Added:
- Keywords can now be used as names or attribute values (#363).
  Graphviz keywords like "graph" or "subgraph" will now be properly quoted
  when used as attribute values or as names, where appropriate.
- Add standard Python logging, using the logger name `pydot`. For
  details, see the new section on Troubleshooting in README.md.


2.0.0 (2023-12-30)
------------------

Changed:
- Broken parsing caused by `pyparsing` updates fixed. (#296)
  With this, the pydot project rises from the dead.
- (Internal) CI revived by @ferdnyc. (#302)
  Modernized and clarified the development process.
  Testing is done against multiple Python versions.
- Reorganized package/module structure. (#230)
  The `pydot` package is installed as a directory now instead of as
  two modules:

      Before (pydot 0.x, 1.x)    After (pydot 2.x)

      site-packages/             site-packages/
      |-- pydot.py               `-- pydot/
      `-- dot_parser.py              |-- __init__.py
                                     |-- core.py
                                     |-- dot_parser.py
                                     `-- exceptions.py

  This is mostly an internal change that should go unnoticed by most
  users, especially those upgrading through `pip` or a software
  distribution. `import pydot` should work as it did before.
  Special cases:
  - `import dot_parser` no longer works. Change it to
    `from pydot import dot_parser` or see if you can use the wrappers
    `pydot.graph_from_dot_data()` or `pydot.graph_from_dot_file()`.

    **USER FEEDBACK REQUESTED**
    We assume pydot users do not often directly `import dot_parser`.
    If you do, please report your reasons, so that we can consider
    making it available again before the final release of pydot 2.0:
    https://github.com/pydot/pydot/issues/230

  - If you use pydot from a (cloned) pydot source tree:
    - The pydot source modules moved from the top directory to
      subdirectory `src/pydot/`.
    - When using a `PYTHONPATH` environment variable: Append `/src`,
      e.g. `PYTHONPATH=~/Development/pydot/src`. If you need to switch
      between pydot 1.x and pydot 2.x, add both, e.g.
      `PYTHONPATH=~/Development/pydot/src:~/Development/pydot`
    - When using an editable install (development mode): Re-run
      `pip install -e .` from the top directory of the source tree to
      update the links.
  - For users of the test suite:
    - The test suite no longer refuses to run from the top of the
      source tree.
    - This makes the test suite option `--no-check` redundant. It has
      no effect except for printing a deprecation warning. It will be
      removed in a future major release (pydot 3 or higher), then
      leading to an error.
- Reorganized exception hierarchy: (#230)
  - New base class `PydotException`, derived from Python's `Exception`.
  - Pydot's `Error` exception class is now derived from `PydotException`
    instead of from Python's built-in `Exception` directly. Existing
    handlers should not be affected.
  - Exception class `InvocationException` was removed. It has not been
    raised by pydot since 2016 (v1.2.0).

- API (minor): Renamed the first parameter of the parser functions
  listed below from `str` to `s`. These functions primarily exist for
  internal use and would normally be called using positional arguments,
  so few users should be affected. (#229)
      push_top_graph_stmt(s, loc, toks)
      push_graph_stmt(s, loc, toks)
      push_subgraph_stmt(s, loc, toks)
      push_default_stmt(s, loc, toks)
      push_attr_list(s, loc, toks)
      push_edge_stmt(s, loc, toks)

Deprecated:
- Test suite option `--no-check`. See "Reorganized package/module
  structure" above.

Removed:
- Drop support for Python 2 and Python < 3.7. (#229, #302, #296).
  **USER FEEDBACK REQUESTED**
  ~~We are considering if pydot 2.0 should drop support for Python 3.5
  and 3.6 as well. If this would affect you, please leave a comment in
  https://github.com/pydot/pydot/issues/268.~~
  EDIT: This was decided to be done, with a lot of time passed since this entry.


1.4.2 (2021-02-15)
------------------

Added:
- Documentation: Basic usage examples in `README.md`. (#141)

Changed:
- More detailed error message in case of Graphviz errors. (#239)
- More detailed warning message in case of failure to import the DOT
  parser module. (#241)

Deprecated:
- A future pydot 2.0.0 will drop support for Python 2, 3.4 and
  possibly other Python versions that are end-of-life at that time.
  Pydot does not emit any deprecation warnings about this. Further
  pydot 1.x.x releases are currently not foreseen, but if there are
  any, should still support the mentioned Python versions. (#229)

Fixed:
- On Python 2, non-equality comparison (`!=`) between two separate, but
  equal `Edge` instances will now correctly return `False`, as it
  already did on Python 3. (#248)
- Prevent `TypeError` in handling of DOT parser error. (#176)
- Prevent `TypeError` in `graph_from_adjacency_matrix()` and
  `graph_from_incidence_matrix()`. (#98)
- Prevent `TypeError` when creating an edge with a `Subgraph` or
  `Cluster` object (as opposed to name string) as an edge point. (#89)
- Windows only: Fixed most failures to find Graphviz when a conda or
  Anaconda installation exists, but Graphviz was installed manually or
  through pip (`.bat`/`.exe` suffix problem). (#205)
- Windows only: Fixed failure to run Graphviz related to side-by-side
  assembly (SxS) by now propagating the `SYSTEMROOT` environment
  variable. (#208)


1.4.1 (2018-12-12)
------------------

- Make graph, edge, node attributes order deterministic
- Fix string formatting after catching error (#201)


1.4.0 (2018-12-01)
------------------

- Installation of pydot in conda env on Windows directly supported
- Fixed comparing of SHA hash in regression tests (which fail now)


1.3.0 (2018-11-19)
------------------

- Dropped Python 2.6 support (#185)
- Move errno from os to builtin. Fixes #177 (#191, #182)


1.2.4 (2017-12-25)
------------------

- ENH: propagate `LD_LIBRARY_PATH` when calling GraphViz
- API: raise `OSError` when a GraphViz executable is not found
- API: add method `__str__` to classes `Node, Edge, Graph`
- API: add arg `encoding` to `Dot` methods `create, write`
- API: quote cluster names when necessary
- API: give source and destination nodes as separate args to `Edge.__init__`
- API: never ignore `src, dst`, overwrite if `points` defined in `obj_dict`


1.2.3 (2016-10-06)
------------------

- support Python 2.6
- several corrections
- quote empty strings to avoid graphviz errors


1.2.0 (2016-07-01)
------------------

- support Python 3
- bumped dependency to `pyparsing >= 2.1.4`
- tests running on Travis CI
- tests require `chardet`
- detect character encoding for most test files
  using the package `chardet`

API:

- on all operating systems, search GraphViz
  executables in environment `$PATH`,
  using `subprocess.Popen`.
  No paths hard-coded due to security and privacy issues.

- add option to pass GraphViz executable name
  or absolute path as `prog` to `pydot.Dot.write_*` methods.
  This provides an alternative to
  adding GraphViz to the `$PATH`.

- the functions:
    - `pydot.graph_from_dot_data`
    - `pydot.graph_from_dot_file`
    - `dot_parser.parse_dot_data`
  changed to always return a `list` of graphs,
  instead of behaving differently for singletons.

- require that the user explicitly give an encoding to
  the function `pydot.graph_from_dot_file`,
  with default encoding same as `io.open`.

- decode to unicode at program boundaries, and
  treat binary images as bytes,
  for more compatibility with python 3.
  Use `io.open`, instead of the built-in `open`.

- rm function `pydot.set_graphviz_executables`

- rm attribute `pydot.Dot.progs`


1.1.0 (2016-05-23)
------------------

- compatibility with `pyparsing >= 1.5.7`

API:

- `pydot.Graph.to_string`: hide `subgraph` keyword only if so requested
- produce `warnings.warn` if `pydot.dot_parser` fails to import,
  instead of `print`


1.0.29 (2016-05-16)
-------------------

- Maintenance release that keeps the same API
- pin `pyparsing == 1.5.7`
- update version number in source code
- update `setup.py`


1.0.28 (2012-01-03)
-------------------

- Fixed issue 52. Improved handling of BOM-less UTF-8 encoded files.
- Fixed issue 55 regarding unicode handling.
- Fixed issue 50 where an ending colon in a node name was understood
  as a port separator. Colons as the last character of node names will
  be left as-is.
- Issue 59 (and duplicate issue 62): Program arguments are mishandled
  in `Dot.create` - Patch merged.
- Fixed issue 49, handling of quotes in unicode html-labels.
- Fixed issue 60. Added an additional check in `__get_attribute__` to not
  assume the parent graph is always retrievable.
- Fixed issue 61. Graph names will be adequately quoted when necessary.


1.0.25 (2011-04-10)
-------------------

- Improved the message raised by `TypeErrors`.
- If arguments need to be specified for 'dot', 'neato' and rest of
  graph layout engines they can now be passed to the `create()` and
  `create_*()` family of functions. If a string is passed it's expected
  to be simply the name of the program. If a list is passed it's
  assumed to contain strings, the name of the layout engine as the
  first element, followed by any optional arguments that will be later
  appended to the command line.
- Improved parsing of DOT files where a subgraph was given inline as
  the source or destination of an edge.


1.0.23 (around 2011-03-03)
--------------------------

- Fixed Issue 46 and modified the version number to include the
  subversion revision number, hence the small jump from 1.0.4 to 1.0.23
  ;-)


1.0.4 (2010-12-31)
------------------

- Merged fixes by Nelson Elhage
  - The "id_re_with_port" regex was too lax, and let through many
    illegal strings just because they contained colons. Fix it to
    require that both the ID and port component be independently safe.
  - Even when the code detected that a string needed quoting, ", \n,
    and \r were left alone inside the double quotes, which is illegal.
    Replace them with appropriately escaped versions.
- We also add a test that pydot is correctly able to quote Python's
  "string.printable" string, which exercises both of the above cases.
- Added testing script and test data
- Fixed issue 42. Graphviz's executable "sfdp" has been included in the
  list of executables to search for and will now be found if available.
- Updated main docstring
- Fixed setup.py script to not include the dot-underscore files in OSX
  (the resource fork) when building the tar.gz for distribution


1.0.3 (2010-11-02)
------------------

The release 1.0.3 of **pydot** is mainly a maintenance release. It
badly needed some attention. Most of the open issues have been
addressed.

dot_parser.py:
- Improved the parsing of attributes with no explicit value but
  implicit defaults
- Improved handling of subgraphs
- Improved handling of whitespace within HTML node names/labels

pydot.py:
- Updated Graph, Cluster, Subgraph, Node and Edge attributes to reflect
  the latest GraphViz version (2.26.3)
- Improved the parsing of attributes with no explicit value but
  implicit defaults
- Improved handling of boolean attributes
- Fixed issue 17, 12
- Fixed issues 19, 29, 35, 37 finding the Graphviz binary in Windows
- Added method del_node() to delete Nodes from the graph
- Added method del_edges() to delete Edges from the graph
- get_node() will now always return a list of nodes
- get_edge() will now always return a list of edges
- get_subgraph() will now always return a list of edges
- Other minor improvements


1.0.2 (2008-02-14)
------------------

The release 1.0.2 of **pydot** boasts the following:

- The parser has been improved a lot. It passes all of GraphViz's
  regression tests (which I consider quite an accomplishment seeing the
  kind of crazy constructs on those )
- Different charsets should now be dealt with properly.
- The search of GraphViz's executables has been improved for all
  platforms. On Windows, paths and registry keys are searched. On Unix
  now it should exhibit the same behavior as the traditional shell path
  search. (Thanks Andy Gimblett and many others)
- Double-quoted paths in Windows are nor properly handled. The
  os.path.exists() check fails if a valid path is enclosed within
  quotes.
- 'type' keyword has been changed everywhere to 'graph_type'
- Better handling of Node/Edge/Graph defaults. Added methods:
  set_graph_defaults, set_node_defaults, set_edge_defaults,
  get_graph_defaults, get_node_defaults, get_edge_defaults
- Now it's possible to use rank to lay out nodes at the same level

      graph = pydot.Dot('graphname', graph_type='digraph')
      subg = pydot.Subgraph('', rank='same')
      subg.add_node(pydot.Node('a'))
      graph.add_subgraph(subg)
      subg.add_node(pydot.Node('b'))
      subg.add_node(pydot.Node('c'))

- Multiple main graphs in a file are now supported, will be returned as
  a list of graph instances
- Handling of shapefiles Dot().set_shape_files()
- Added method "add_style()" to the Node class to easily append styles
  to a node
- Attribute lists updated to reflect the available ones in graphviz 2.16
- Added error reporting when rendering graphs with GraphViz
  executables. There was an often reported problem where the output
  graphs would have 0 size. In most cases this was due to Graphviz
  missing a library for a format that pydot assumed to be there. Now
  the error given by the executable will be reported instead of being
  silently ignored (Thanks Jarno)
- Improved parsing of identifiers
- Added non-GraphViz attributes needed by dot2tex
- Jose Fonseca contributed a fix dealing with quoted strings the the
  dot parsing module
- setup.py updated so that it's possible to install pydot through
  Setuptools' easy_install
- Edge()'s can be created passing two Node objects as well as, the
  previously supported, two strings with node names. Warning: when
  passing two Node instances, the attributes won't be taken into
  account. The edge will only read the Nodes' names to create an edge,
  the Nodes must be separately added to the graph so all their
  attributes are "remembered".
- Substituted all str()'s for unicode()'s
- It's possible now to manually specify the path to GraphViz's
  executables in the case they can't be found automatically. The method
  'set_graphviz_executables(paths)' will take a dictionary specifying
  the location of the executables. Please refer to the documentation
  for usage detailed information.
- And too many bugfixes to list...

**Performance:**

The new pydot stores graphs and their objects using a hierarchy of
nested dictionaries and lists. Graph, Node, Edge objects are mere
proxies to the data and are created on demand. So that now it's
possible to have a graph with a 1 million edges and there will not be a
single Edge instance (only if requested, then they will be created on
demand, mapping the data and providing with all the methods to act on
the data in the global dictionary).

Storing a graph with 1 million edges in pydot 1.0 has approximately the
same memory requirements (~813MiB) as dealing with one with only 40.000
edges in pydot 0.9 (~851MiB), the 40.000 edges graph needs ~35MiB in
pydot 1.0 . Handling graphs should be much faster, as no linear
searches are performed in pydot 1.0


0.9.10 (2004-12-21) and earlier
-------------------------------

2004-12-21 09:12  carrer

	* dot_parser.py, pydot.py: Updated docstrings

2004-12-20 11:19  carrer

	* dot_parser.py: Parsing of dot files greatly improved

2004-12-20 11:17  carrer

	* pydot.py: Added new attributes introduced in Graphviz 1.16.
	  Added support to pickle graphs.  Parsing of dot files greatly
	  improved.  Bumped version to 0.9.10.

2004-12-14 07:48  carrer

	* pydot.py: Improved the processing of the graph's default values

2004-10-11 21:10  carrer

	* README:
	  Added list of required software to the README

2004-10-11 21:09  carrer

	* MANIFEST, setup.py:
	  Added dot_parser module

2004-10-11 21:06  carrer

	* dot_parser.py, pydot.py:
	  Thanks to a great contribution from Michael Krause, pydot is now
	  able to load DOT files. The loader has been tested against
	  plethora of test DOT files, and the results written to PS files,
	  which ended up being identical to the ones obtained straight from
	  running them through dot. Functions 'graph_from_dot_file' and
	  'graph_from_dot_data' have been added. This feature requires the
	  pyparsing module.

	  Note that if using pyparsing <1.2 the tabs in labels are
	  converted to whitespaces. 1.2 fixed that.

	  Adrian Heilbut noticed that there was no way of telling pydot to
	  create HTML labels. Starting from this version, if the label's
	  first character is '<' and last is '>', the label will be treated
	  as HTML.  If this is not the desired behaviour it suffices with
	  adding a whitespace before the first '<' character or after the
	  last '>'.

	  Version bumped to 0.9.9

2004-10-11 21:02  carrer

	* pydot.py:
	  Added check to add_node() avoid creating nodes with the same
	  names.

2004-10-11 20:59  carrer

	* pydot.py:
	  When adding an edge through add_edge() the correspoding Node
	  objects were not being created. While the graph was correctly
	  displayed it was not possible to modify the node attributes, as
	  it did not exist. Thus now, everytime an edge is added, the
	  corresponding nodes are created if they did not previously exist.

2004-07-08 01:44  carrer

	* pydot.py: Fixed bug reported by Hector Villafuerte.

2004-07-08 00:11  carrer

	* pydot.py: Fixed bug reported by Colin Gillespie regarding the
	  problem creating clusters due to the 'simplify' attribute
	  missing.

2004-07-07 23:51  carrer

	* pydot.py: Set default program with which to process the output
	  and added some minor enhacement enabling to pass non-str objects
	  as Node names, which will be converted to str by retrieving their
	  string representation with str()

2004-05-20 10:47  carrer

	* pydot.py: Bumped version to 0.9.4

2004-05-20 10:41  carrer

	* pydot.py: Minor bugfix

2004-05-03 23:45  carrer

	* pydot.py: Merged fixes by Ramon Felciano: -Better handling of
	  default 'node' and 'edge' definitions.  -Subgraph class now
	  accepts the same parametes as Graph.

2004-05-01 14:24  carrer

	* README, setup.py: Changed license from GPL to MIT.

2004-05-01 14:00  carrer

	* pydot.py: Minor bugfix.  Added methods to retrieve an edge's
	  source and destination.

2004-05-01 13:49  carrer

	* pydot.py: Minor bugfixes.  License has been changed from GPL to
	  MIT.	The following features have been implemented, as suggested
	  by Ramon Felciano:  -Ability to retrieve nodes/subgraphs (by
	  name) and edges (by src+target) from a graph.   -Ability to get
	  the graph's node/edge/subgraph lists.   -Ability to get the
	  attributes from the objects, not only set them.

2004-05-01 13:34  carrer

	* LICENSE: Changed license from GPL to MIT.

2004-04-28 21:52  carrer

	* ChangeLog: [no log message]

2004-04-28 21:50  carrer

	* pydot.py: Some of the changes already made should allow pydot to
	  run on OSX.  Bumped version to 0.9.2

2004-04-24 17:52  carrer

	* setup.py: Added more metainformation to the distribution.

2004-04-24 17:51  carrer

	* pydot.py: Added support for circo and fdp. Fixed piping mechanism
	  to not to capture stderr.

2004-04-24 13:26  carrer

	* ChangeLog, LICENSE, MANIFEST, README, setup.py: Adding
	  supplementary files to the distribution to the CVS.

2004-04-24 12:57  carrer

	* pydot.py: Bumped version to 0.9.1

2004-04-24 01:36  carrer

	* pydot.py: Implemented tweaks suggested by John B. Cole to handle
	  non-str nodes, converting them to strings.

2004-04-24 01:10  carrer

	* pydot.py: Applied patch for Windows support by Kent Johnson.

2004-04-24 01:05  carrer

	* pydot.py: Fixed to properly handle unicode strings in attributes.

2004-04-20 00:06  carrer

	* pydot.py:
	  Fixed silly error in graph_from_edges. When pasting the function
	  into the code, the references to the pydot module were not
	  removed, which are no longer needed since we now are _in_ the
	  module.

2004-04-19 23:33  carrer

	* pydot.py:
	  Added support to write files with the desired output format with
	  write_[format]

2004-04-19 22:53  carrer

	* pydot.py:
	  Done some clean up, no major changes.

2004-04-08 00:22  carrer

	* pydot.py:
	  Initial revision.

2004-04-08 00:22  carrer

	* pydot.py: Initial revision