# -*- coding: utf-8 -*- """This module provides utility functions for the Draft Workbench. This module should contain auxiliary functions which don't require the graphical user interface (GUI). """ ## @package utils # \ingroup DRAFT # \brief This module provides utility functions for the Draft Workbench # *************************************************************************** # * (c) 2009, 2010 * # * Yorik van Havre , Ken Cline * # * (c) 2019 Eliud Cabrera Castillo * # * * # * This file is part of the FreeCAD CAx development system. * # * * # * This program is free software; you can redistribute it and/or modify * # * it under the terms of the GNU Lesser General Public License (LGPL) * # * as published by the Free Software Foundation; either version 2 of * # * the License, or (at your option) any later version. * # * for detail see the LICENCE text file. * # * * # * FreeCAD is distributed in the hope that it will be useful, * # * but WITHOUT ANY WARRANTY; without even the implied warranty of * # * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * # * GNU Library General Public License for more details. * # * * # * You should have received a copy of the GNU Library General Public * # * License along with FreeCAD; if not, write to the Free Software * # * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * # * USA * # * * # *************************************************************************** import os import FreeCAD from PySide import QtCore import Draft_rc App = FreeCAD # The module is used to prevent complaints from code checkers (flake8) True if Draft_rc else False if App.GuiUp: # The right translate function needs to be imported here # from DraftGui import translate # At the moment it is the same function as without GUI def translate(context, text): return text else: def translate(context, text): return text def _tr(text): """Function to translate with the context set.""" return translate("Draft", text) def _msg(text, end="\n"): App.Console.PrintMessage(text + end) def _wrn(text, end="\n"): App.Console.PrintWarning(text + end) def _log(text, end="\n"): App.Console.PrintLog(text + end) ARROW_TYPES = ["Dot", "Circle", "Arrow", "Tick", "Tick-2"] arrowtypes = ARROW_TYPES def string_encode_coin(ustr): """Encode a unicode object to be used as a string in coin Parameters ---------- ustr : str A string to be encoded Returns ------- str Encoded string. If the coin version is >= 4 it will encode the string to `'utf-8'`, otherwise it will encode it to `'latin-1'`. """ try: from pivy import coin coin4 = coin.COIN_MAJOR_VERSION >= 4 except (ImportError, AttributeError): coin4 = False if coin4: return ustr.encode('utf-8') else: return ustr.encode('latin1') stringencodecoin = string_encode_coin def type_check(args_and_types, name="?"): """Check that the arguments are instances of certain types. Parameters ---------- args_and_types : list A list of tuples. The first element of a tuple is tested as being an instance of the second element. :: args_and_types = [(a, Type), (b, Type2), ...] Then :: isinstance(a, Type) isinstance(b, Type2) A `Type` can also be a tuple of many types, in which case the check is done for any of them. :: args_and_types = [(a, (Type3, int, float)), ...] isinstance(a, (Type3, int, float)) name : str, optional Defaults to `'?'`. The name of the check. Raises ------- TypeError If the first element in the tuple is not an instance of the second element, it raises `Draft.name`. """ for v, t in args_and_types: if not isinstance(v, t): w = "typecheck[" + str(name) + "]: " w += str(v) + " is not " + str(t) + "\n" FreeCAD.Console.PrintWarning(w) raise TypeError("Draft." + str(name)) typecheck = type_check def get_param_type(param): """Return the type of the parameter entered. Parameters ---------- param : str A string that indicates a parameter in the parameter database. Returns ------- str or None The returned string could be `'int'`, `'string'`, `'float'`, `'bool'`, `'unsigned'`, depending on the parameter. It returns `None` for unhandled situations. """ if param in ("dimsymbol", "dimPrecision", "dimorientation", "precision", "defaultWP", "snapRange", "gridEvery", "linewidth", "UiMode", "modconstrain", "modsnap", "maxSnapEdges", "modalt", "HatchPatternResolution", "snapStyle", "dimstyle", "gridSize"): return "int" elif param in ("constructiongroupname", "textfont", "patternFile", "template", "snapModes", "FontFile", "ClonePrefix", "labeltype") or "inCommandShortcut" in param: return "string" elif param in ("textheight", "tolerance", "gridSpacing", "arrowsize", "extlines", "dimspacing", "dimovershoot", "extovershoot"): return "float" elif param in ("selectBaseObjects", "alwaysSnap", "grid", "fillmode", "saveonexit", "maxSnap", "SvgLinesBlack", "dxfStdSize", "showSnapBar", "hideSnapBar", "alwaysShowGrid", "renderPolylineWidth", "showPlaneTracker", "UsePartPrimitives", "DiscretizeEllipses", "showUnit"): return "bool" elif param in ("color", "constructioncolor", "snapcolor", "gridColor"): return "unsigned" else: return None getParamType = get_param_type def get_param(param, default=None): """Return a paramater value from the current parameter database. The parameter database is located in the tree :: 'User parameter:BaseApp/Preferences/Mod/Draft' In the case that `param` is `'linewidth'` or `'color'` it will get the values from the View parameters :: 'User parameter:BaseApp/Preferences/View/DefaultShapeLineWidth' 'User parameter:BaseApp/Preferences/View/DefaultShapeLineColor' Parameters ---------- param : str A string that indicates a parameter in the parameter database. default : optional It indicates the default value of the given parameter. It defaults to `None`, in which case it will use a specific value depending on the type of parameter determined with `get_param_type`. Returns ------- int, or str, or float, or bool Depending on `param` and its type, by returning `ParameterGrp.GetInt`, `ParameterGrp.GetString`, `ParameterGrp.GetFloat`, `ParameterGrp.GetBool`, or `ParameterGrp.GetUnsinged`. """ draft_params = "User parameter:BaseApp/Preferences/Mod/Draft" view_params = "User parameter:BaseApp/Preferences/View" p = FreeCAD.ParamGet(draft_params) v = FreeCAD.ParamGet(view_params) t = getParamType(param) # print("getting param ",param, " of type ",t, " default: ",str(default)) if t == "int": if default is None: default = 0 if param == "linewidth": return v.GetInt("DefaultShapeLineWidth", default) return p.GetInt(param, default) elif t == "string": if default is None: default = "" return p.GetString(param, default) elif t == "float": if default is None: default = 0 return p.GetFloat(param, default) elif t == "bool": if default is None: default = False return p.GetBool(param, default) elif t == "unsigned": if default is None: default = 0 if param == "color": return v.GetUnsigned("DefaultShapeLineColor", default) return p.GetUnsigned(param, default) else: return None getParam = get_param def set_param(param, value): """Set a Draft parameter with the given value The parameter database is located in the tree :: 'User parameter:BaseApp/Preferences/Mod/Draft' In the case that `param` is `'linewidth'` or `'color'` it will set the View parameters :: 'User parameter:BaseApp/Preferences/View/DefaultShapeLineWidth' 'User parameter:BaseApp/Preferences/View/DefaultShapeLineColor' Parameters ---------- param : str A string that indicates a parameter in the parameter database. value : int, or str, or float, or bool The appropriate value of the parameter. Depending on `param` and its type, determined with `get_param_type`, it sets the appropriate value by calling `ParameterGrp.SetInt`, `ParameterGrp.SetString`, `ParameterGrp.SetFloat`, `ParameterGrp.SetBool`, or `ParameterGrp.SetUnsinged`. """ draft_params = "User parameter:BaseApp/Preferences/Mod/Draft" view_params = "User parameter:BaseApp/Preferences/View" p = FreeCAD.ParamGet(draft_params) v = FreeCAD.ParamGet(view_params) t = getParamType(param) if t == "int": if param == "linewidth": v.SetInt("DefaultShapeLineWidth", value) else: p.SetInt(param, value) elif t == "string": p.SetString(param, value) elif t == "float": p.SetFloat(param, value) elif t == "bool": p.SetBool(param, value) elif t == "unsigned": if param == "color": v.SetUnsigned("DefaultShapeLineColor", value) else: p.SetUnsigned(param, value) setParam = set_param def precision(): """Return the precision value from the paramater database. It is the number of decimal places that a float will have. Example :: precision=6, 0.123456 precision=5, 0.12345 precision=4, 0.1234 Due to floating point operations there may be rounding errors. Therefore, this precision number is used to round up values so that all operations are consistent. By default the precision is 6 decimal places. Returns ------- int get_param("precision", 6) """ return getParam("precision", 6) def tolerance(): """Return the tolerance value from the parameter database. This specifies a tolerance around a quantity. :: value + tolerance value - tolerance By default the tolerance is 0.05. Returns ------- float get_param("tolerance", 0.05) """ return getParam("tolerance", 0.05) def epsilon(): """Return a small number based on the tolerance for use in comparisons. The epsilon value is used in floating point comparisons. Use with caution. :: denom = 10**tolerance num = 1 epsilon = num/denom Returns ------- float 1/(10**tolerance) """ return 1.0/(10.0**tolerance()) def get_real_name(name): """Strip the trailing numbers from a string to get only the letters. Paramaters ---------- name : str A string that may have a number at the end, `Line001`. Returns ------- str A string without the numbers at the end, `Line`. The returned string cannot be empty; it will have at least one letter. """ for i in range(1, len(name)): if name[-i] not in '1234567890': return name[:len(name) - (i-1)] return name getRealName = get_real_name def get_type(obj): """Return a string indicating the type of the given object. Paramaters ---------- obj : App::DocumentObject Any type of scripted object created with Draft, or any other workbench. Returns ------- str If `obj` has a `Proxy`, it will return the value of `obj.Proxy.Type`. * If `obj` is a `Part.Shape`, returns `'Shape'` * If `'Sketcher::SketchObject'`, returns `'Sketch'` * If `'Part::Line'`, returns `'Part::Line'` * If `'Part::Offset2D'`, returns `'Offset2D'` * If `'Part::Feature'`, returns `'Part'` * If `'App::Annotation'`, returns `'Annotation'` * If `'Mesh::Feature'`, returns `'Mesh'` * If `'Points::Feature'`, returns `'Points'` * If `'App::DocumentObjectGroup'`, returns `'Group'` * If `'App::Part'`, returns `'App::Part'` In other cases, it will return `'Unknown'`, or `None` if `obj` is `None`. """ import Part if not obj: return None if isinstance(obj, Part.Shape): return "Shape" if "Proxy" in obj.PropertiesList: if hasattr(obj.Proxy, "Type"): return obj.Proxy.Type if obj.isDerivedFrom("Sketcher::SketchObject"): return "Sketch" if (obj.TypeId == "Part::Line"): return "Part::Line" if (obj.TypeId == "Part::Offset2D"): return "Offset2D" if obj.isDerivedFrom("Part::Feature"): return "Part" if (obj.TypeId == "App::Annotation"): return "Annotation" if obj.isDerivedFrom("Mesh::Feature"): return "Mesh" if obj.isDerivedFrom("Points::Feature"): return "Points" if (obj.TypeId == "App::DocumentObjectGroup"): return "Group" if (obj.TypeId == "App::Part"): return "App::Part" return "Unknown" getType = get_type def get_objects_of_type(objects, typ): """Return only the objects that match the type in the list of objects. Parameters ---------- objects : list of App::DocumentObject A list of objects which will be tested. typ : str A string that indicates a type. This should be one of the types that can be returned by `get_type`. Returns ------- list of objects Only the objects that match `typ` will be added to the output list. """ objs = [] for o in objects: if getType(o) == typ: objs.append(o) return objs getObjectsOfType = get_objects_of_type def is_clone(obj, objtype, recursive=False): """Return True if the given object is a clone of a certain type. A clone is of type `'Clone'`, and has a reference to the original object inside its `Objects` attribute, which is an `'App::PropertyLinkListGlobal'`. The `Objects` attribute can point to another `'Clone'` object. If `recursive` is `True`, the function will be called recursively to further test this clone, until the type of the original object can be compared to `objtype`. Parameters ---------- obj : App::DocumentObject The clone object that will be tested for a certain type. objtype : str or list of str A type string such as one obtained from `get_type`. Or a list of such types. recursive : bool, optional It defaults to `False`. If it is `True`, this same function will be called recursively with `obj.Object[0]` as input. This option only works if `obj.Object[0]` is of type `'Clone'`, that is, if `obj` is a clone of a clone. Returns ------- bool Returns `True` if `obj` is of type `'Clone'`, and `obj.Object[0]` is of type `objtype`. If `objtype` is a list, then `obj.Objects[0]` will be tested against each of the elements in the list, and it will return `True` if at least one element matches the type. If `obj` isn't of type `'Clone'` but has the `CloneOf` attribute, it will also return `True`. It returns `False` otherwise, for example, if `obj` is not even a clone. """ if isinstance(objtype, list): return any([isClone(obj, t, recursive) for t in objtype]) if getType(obj) == "Clone": if len(obj.Objects) == 1: if getType(obj.Objects[0]) == objtype: return True elif recursive and (getType(obj.Objects[0]) == "Clone"): return isClone(obj.Objects[0], objtype, recursive) elif hasattr(obj, "CloneOf"): if obj.CloneOf: return True return False isClone = is_clone def get_group_names(): """Return a list of names of existing groups in the document. Returns ------- list of str A list of names of objects that are "groups". These are objects derived from `'App::DocumentObjectGroup'` or which are of types `'Floor'`, `'Building'`, or `'Site'` (from the Arch Workbench). Otherwise, return an empty list. """ glist = [] doc = FreeCAD.ActiveDocument for obj in doc.Objects: if (obj.isDerivedFrom("App::DocumentObjectGroup") or getType(obj) in ("Floor", "Building", "Site")): glist.append(obj.Name) return glist getGroupNames = get_group_names def ungroup(obj): """Remove the object from any group to which it belongs. A "group" is any object returned by `get_group_names`. Parameters ---------- obj : App::DocumentObject Any type of scripted object. """ for name in getGroupNames(): group = FreeCAD.ActiveDocument.getObject(name) if obj in group.Group: # The list of objects cannot be modified directly, # so a new list is created, this new list is modified, # and then it is assigned over the older list. objects = group.Group objects.remove(obj) group.Group = objects def shapify(obj): """Transform a parametric object into a static, non-parametric shape. Parameters ---------- obj : App::DocumentObject Any type of scripted object. This object will be removed, and a non-parametric object with the same topological shape (`Part::TopoShape`) will be created. Returns ------- Part::Feature The new object that takes `obj.Shape` as its own. Depending on the contents of the Shape, the resulting object will be named `'Face'`, `'Solid'`, `'Compound'`, `'Shell'`, `'Wire'`, `'Line'`, `'Circle'`, or the name returned by `get_real_name(obj.Name)`. If there is a problem with `obj.Shape`, it will return `None`, and the original object will not be modified. """ try: shape = obj.Shape except Exception: return None if len(shape.Faces) == 1: name = "Face" elif len(shape.Solids) == 1: name = "Solid" elif len(shape.Solids) > 1: name = "Compound" elif len(shape.Faces) > 1: name = "Shell" elif len(shape.Wires) == 1: name = "Wire" elif len(shape.Edges) == 1: import DraftGeomUtils if DraftGeomUtils.geomType(shape.Edges[0]) == "Line": name = "Line" else: name = "Circle" else: name = getRealName(obj.Name) FreeCAD.ActiveDocument.removeObject(obj.Name) newobj = FreeCAD.ActiveDocument.addObject("Part::Feature", name) newobj.Shape = shape return newobj def get_windows(obj): """Return the windows and rebars inside a host. Parameters ---------- obj : App::DocumentObject A scripted object of type `'Wall'` or `'Structure'` (Arch Workbench). This will be searched for objects of type `'Window'` and `'Rebar'`, and clones of them, and the found elements will be added to the output list. The function will search recursively all elements under `obj.OutList`, in case the windows and rebars are nested under other walls and structures. Returns ------- list A list of all found windows and rebars in `obj`. If `obj` is itself a `'Window'` or a `'Rebar'`, or a clone of them, it will return the same `obj` element. """ out = [] if getType(obj) in ("Wall", "Structure"): for o in obj.OutList: out.extend(get_windows(o)) for i in obj.InList: if getType(i) in ("Window") or isClone(obj, "Window"): if hasattr(i, "Hosts"): if obj in i.Hosts: out.append(i) elif getType(i) in ("Rebar") or isClone(obj, "Rebar"): if hasattr(i, "Host"): if obj == i.Host: out.append(i) elif (getType(obj) in ("Window", "Rebar") or isClone(obj, ["Window", "Rebar"])): out.append(obj) return out getWindows = get_windows def get_group_contents(objectslist, walls=False, addgroups=False, spaces=False, noarchchild=False): """Return a list of objects from expanding the input groups. The function accepts any type of object, although it is most useful with "groups", as it is meant to unpack the objects inside these groups. Parameters ---------- objectslist : list If any object in the list is a group, its contents (`obj.Group`) are extracted and added to the output list. The "groups" are objects derived from `'App::DocumentObjectGroup'`, but they can also be `'App::Part'`, or `'Building'`, `'BuildingPart'`, `'Space'`, and `'Site'` from the Arch Workbench. Single items that aren't groups are added to the output list as is. walls : bool, optional It defaults to `False`. If it is `True`, Wall and Structure objects (Arch Workbench) are treated as groups; they are scanned for Window, Door, and Rebar objects, and these are added to the output list. addgroups : bool, optional It defaults to `False`. If it is `True`, the group itself is kept as part of the output list. spaces : bool, optional It defaults to `False`. If it is `True`, Arch Spaces are treated as groups, and are added to the output list. noarchchild : bool, optional It defaults to `False`. If it is `True`, the objects inside Building and BuildingParts (Arch Workbench) aren't added to the output list. Returns ------- list The list of objects from each group present in `objectslist`, plus any other individual object given in `objectslist`. """ newlist = [] if not isinstance(objectslist, list): objectslist = [objectslist] for obj in objectslist: if obj: if (obj.isDerivedFrom("App::DocumentObjectGroup") or (getType(obj) in ("App::Part", "Building", "BuildingPart", "Space", "Site") and hasattr(obj, "Group"))): if getType(obj) == "Site": if obj.Shape: newlist.append(obj) if obj.isDerivedFrom("Drawing::FeaturePage"): # skip if the group is a page newlist.append(obj) else: if addgroups or (spaces and getType(obj) == "Space"): newlist.append(obj) if (noarchchild and getType(obj) in ("Building", "BuildingPart")): pass else: newlist.extend(getGroupContents(obj.Group, walls, addgroups)) else: # print("adding ", obj.Name) newlist.append(obj) if walls: newlist.extend(getWindows(obj)) # Clean possible duplicates cleanlist = [] for obj in newlist: if obj not in cleanlist: cleanlist.append(obj) return cleanlist getGroupContents = get_group_contents def print_shape(shape): """Print detailed information of a topological shape. Parameters ---------- shape : Part::TopoShape Any topological shape in an object, usually obtained from `obj.Shape`. """ _msg(_tr("Solids:") + " {}".format(len(shape.Solids))) _msg(_tr("Faces:") + " {}".format(len(shape.Faces))) _msg(_tr("Wires:") + " {}".format(len(shape.Wires))) _msg(_tr("Edges:") + " {}".format(len(shape.Edges))) _msg(_tr("Vertices:") + " {}".format(len(shape.Vertexes))) if shape.Faces: for f in range(len(shape.Faces)): _msg(_tr("Face") + " {}:".format(f)) for v in shape.Faces[f].Vertexes: _msg(" {}".format(v.Point)) elif shape.Wires: for w in range(len(shape.Wires)): _msg(_tr("Wire") + " {}:".format(w)) for v in shape.Wires[w].Vertexes: _msg(" {}".format(v.Point)) else: for v in shape.Vertexes: _msg(" {}".format(v.Point)) printShape = print_shape def compare_objects(obj1, obj2): """Print the differences between 2 objects. The two objects are compared through their `TypeId` attribute, or by using the `get_type` function. If they are the same type their properties are compared looking for differences. Neither `Shape` nor `Label` attributes are compared. Parameters ---------- obj1 : App::DocumentObject Any type of scripted object. obj2 : App::DocumentObject Any type of scripted object. """ if obj1.TypeId != obj2.TypeId: _msg("'{0}' ({1}), '{2}' ({3}): ".format(obj1.Name, obj1.TypeId, obj2.Name, obj2.TypeId) + _tr("different types") + " (TypeId)") elif getType(obj1) != getType(obj2): _msg("'{0}' ({1}), '{2}' ({3}): ".format(obj1.Name, get_type(obj1), obj2.Name, get_type(obj2)) + _tr("different types") + " (Proxy.Type)") else: for p in obj1.PropertiesList: if p in obj2.PropertiesList: if p in ("Shape", "Label"): pass elif p == "Placement": delta = obj1.Placement.Base.sub(obj2.Placement.Base) text = _tr("Objects have different placements. " "Distance between the two base points: ") _msg(text + str(delta.Length)) else: if getattr(obj1, p) != getattr(obj2, p): _msg("'{}' ".format(p) + _tr("has a different value")) else: _msg("{} ".format(p) + _tr("doesn't exist in one of the objects")) compareObjects = compare_objects def load_svg_patterns(): """Load the default Draft SVG patterns and user defined patterns. The SVG patterns are added as a dictionary to the `FreeCAD.svgpatterns` attribute. """ import importSVG FreeCAD.svgpatterns = {} # Getting default patterns in the resource file patfiles = QtCore.QDir(":/patterns").entryList() for fn in patfiles: file = ":/patterns/" + str(fn) f = QtCore.QFile(file) f.open(QtCore.QIODevice.ReadOnly) p = importSVG.getContents(str(f.readAll()), 'pattern', True) if p: for k in p: p[k] = [p[k], file] FreeCAD.svgpatterns.update(p) # Get patterns in a user defined file altpat = getParam("patternFile", "") if os.path.isdir(altpat): for f in os.listdir(altpat): if f[-4:].upper() == ".SVG": file = os.path.join(altpat, f) p = importSVG.getContents(file, 'pattern') if p: for k in p: p[k] = [p[k], file] FreeCAD.svgpatterns.update(p) loadSvgPatterns = load_svg_patterns def svg_patterns(): """Return a dictionary with installed SVG patterns. Returns ------- dict Returns `FreeCAD.svgpatterns` if it exists. Otherwise it calls `load_svg_patterns` to create it before returning it. """ if hasattr(FreeCAD, "svgpatterns"): return FreeCAD.svgpatterns else: loadSvgPatterns() if hasattr(FreeCAD, "svgpatterns"): return FreeCAD.svgpatterns return {} svgpatterns = svg_patterns def get_movable_children(objectslist, recursive=True): """Return a list of objects with child objects that move with a host. Builds a list of objects with all child objects (`obj.OutList`) that have their `MoveWithHost` attribute set to `True`. This function is mostly useful for Arch Workbench objects. Parameters ---------- objectslist : list of App::DocumentObject A single scripted object or list of objects. recursive : bool, optional It defaults to `True`, in which case the function is called recursively to also extract the children of children objects. Otherwise, only direct children of the input objects are added to the output list. Returns ------- list List of children objects that have their `MoveWithHost` attribute set to `True`. """ added = [] if not isinstance(objectslist, list): objectslist = [objectslist] for obj in objectslist: # Skips some objects that should never move their children if getType(obj) not in ("Clone", "SectionPlane", "Facebinder", "BuildingPart"): children = obj.OutList if hasattr(obj, "Proxy"): if obj.Proxy: if (hasattr(obj.Proxy, "getSiblings") and getType(obj) not in ("Window")): # children.extend(obj.Proxy.getSiblings(obj)) pass for child in children: if hasattr(child, "MoveWithHost"): if child.MoveWithHost: if hasattr(obj, "CloneOf"): if obj.CloneOf: if obj.CloneOf.Name != child.Name: added.append(child) else: added.append(child) else: added.append(child) if recursive: added.extend(getMovableChildren(children)) return added getMovableChildren = get_movable_children def utf8_decode(text): """Decode the input string and return a unicode string. Python 2: :: str -> unicode unicode -> unicode Python 3: :: str -> str bytes -> str It runs :: try: return text.decode("utf-8") except AttributeError: return text Parameters ---------- text : str, unicode or bytes A str, unicode, or bytes object that may have unicode characters like accented characters. In Python 2, a `bytes` object can include accented characters, but in Python 3 it must only contain ASCII literal characters. Returns ------- unicode or str In Python 2 it will try decoding the `bytes` string and return a `'utf-8'` decoded string. >>> "Aá".decode("utf-8") >>> b"Aá".decode("utf-8") u'A\\xe1' In Python 2 the unicode string is prefixed with `u`, and unicode characters are replaced by their two-digit hexadecimal representation, or four digit unicode escape. >>> "AáBẃCñ".decode("utf-8") u'A\\xe1B\\u1e83C\\xf1' In Python 2 it will always return a `unicode` object. In Python 3 a regular string is already unicode encoded, so strings have no `decode` method. In this case, `text` will be returned as is. In Python 3, if `text` is a `bytes` object, then it will be converted to `str`; in this case, the `bytes` object cannot have accents, it must only contain ASCII literal characters. >>> b"ABC".decode("utf-8") 'ABC' In Python 3 it will always return a `str` object, with no prefix. """ try: return text.decode("utf-8") except AttributeError: return text