Dim A as Integer B = 20 Sub DotIt(X as Double) Select Case A Case 1 B = B + X Case 2 B = B - X Case Else B = 0 End Select End Sub Function GetHalfB() As Integer GetHalfB = B / 2 End Function

' ' Expressions are converted to their Python equivalent ' Array indexing only works if using the vbArray class which ' maps the __call__ method to indexing A = This + That B = SomeCall(10, 20, 30) Dim SomeArray(10) As Integer C = SomeArray(10)

' ' Multi-line and singe-line ifs are converted to blocks in Python If A = 10 Then DoSomething() ElseIf B = 20 Then DoSomethingElse() Else OtherCase() If B = 20 Then C = 0 Else C = 1 End If

' ' With statements allow quick access to properties and methods ' of an object. These will be translated into explicit calls to ' a temporary object (in case of side-effects) With Container.Member .Init .IncrementCounter 43 With .ChildItem .Refresh End With End With

' ' Selects are converted to If blocks with a temporary variable to ' hold the tested variables (in case of side-effects). Case ranges ' and options are handled as additional clauses for the if Select Case A Case 1 B = B + X Case 2 B = B - X Select Case B Case 0 to 10 C = 1 Case 11, 12 C = 2 End Select Case Else B = 0 End Select

' ' Numeric for loops use a helper function to create the underlying ' sequence to be iterated over For I = 1 To 10 B = B + 1 For J = 10 To 0 Step -1 If B = 20 Then Exit For Next J Next I ' ' For Each relies on the underlying object supporting the iteration ' protocol (which might not be the case!) For Each Child in Parent Child.CleanUp Next

' ' While and Do loops are converted to a Python while ' block. While Something %3C%3E 10 Something = Something + 1 Wend ' ' A starting until clause reverses the condition Do Until Something = 5 Something = Something - 1 Loop ' ' A final Until clause will generate an If with a break Do Something = Something - 1 Loop Until Something = 0

' ' Dim statements define the types of variables and perform initialisation ' and so are mapped to helper functions which create python objects that ' try to behave like the VB equivalents Dim A Dim B as Integer, C As String A = 10: B = 30: C = "Hello World" ' ' Where arrays are defined these use a helper function which creates ' a variant of a list which has initial values Dim D(10) As String, E(10, 2, 3) As MyClass D(5) = "Hello" E(1, 1, 2) = New MyClass(20) ' ' ReDim statements use the helper function to resize the underlying list ' objects while retaining the size ReDim Preserve D(5) ReDim C(20)

' ' Try ... Catch statements are converted to try ... except blocks Try a = 1 / 0 Catch ZeroDivisionError As Err a = 1000 Finally b = 1 End Try ' ' If an Exit Try is found then an additional try ... except is created ' to allow breaking out of the current Except clause Try a = 1 / 0 Catch a = 1000 Exit Try b = 2000 Finally b = 1 End Try ' ' If there is a "When" clause then this is implemented as an If block ' However, the behaviour is not likely to be identical in Python in the ' current implementation a = 1 Try a = 1 / 0 Catch ZeroDivisionError When a = 1 a = 1000 b = 2000 Finally b = 1 End Try

' ' Subroutines are converted to Python functions and can ' include optional parameters with defaults ' ' An optional parameter with no default uses the helper ' object VBMissingArgument and the helper function IsMissing Sub MySub(X, Optional Y, Optional Z=20) Dim subLocal If IsMissing(Y) Then Y = 12 subLocal = X + Y + Z + moduleGlobal End Sub MySub 1, 2 MySub 1, Z:=10 ' ' Passing by Value converts but behaves differently for ' immutable types in Python. Sub DoIt(x, ByVal y) x = x + 1 y = y + 1 End Sub x = 0 y = 0 DoIt x, y ' x is now 1, y is still 0

' ' Functions use a variable to store the result of the ' function during its execution Function MyFunc(X, Optional Y, Optional Z=20) Dim subLocal subLocal = X + Y + Z MyFunc = subLocal*10 End Function a = MyFunc(1, 2) a = MyFunc(1, Z:=10)

' ' Types create classes with properties to store the ' values of the types Type Point X As Single Y As Single End Type ' Type Line2D Start As Point Finish As Point End Type ' Dim p1 As Point, p2 As Point p1.X = 10 p1.Y = 20 p2.X = 30 p3.Y = 40 ' Dim l1 As Line2D l1.Start = p1 l1.Finish = p2

' ' Enums create variables with the same names Enum Number One = 1 Two = 2 Three = 3 Four = 4 Ten = 10 Hundred = 100 End Enum Enum Day Mon Tue Wed Thu Fri End Enum

' ' In class modules you can use properties to provide ' accessor functions. These are converted to the Python ' equivalent Dim myValue = 0 Property Let PriceToPublic(Value As Integer) myValue = myValue - Value If myValue %3C 0 Then myValue = 0 End Property Property Get PriceToPublic() PriceToPublic = 2 * myValue End Property

' ' .NET Anonymous functions are converted to Python lambda's Value = CallIt(Function(a, b) a+b) Function CallIt(fn_object) Try Return fn_object(10, 20) Catch Return "There was an error" End Try End Function

' ' In the context of a class module, dimensioned variables ' are converted to attributes of the class and any ' subroutines and functions are converted to methods ' of the class. Dim A as Integer Dim B = 20 Sub DotIt(X as Double) Select Case A Case 1 B = B + X Case 2 B = B - X Case Else B = 0 End Select End Sub Function GetHalfB() As Integer GetHalfB = B / 2 End Function

' ' File operations using #channels are mapped to a helper ' function that keeps track of the open files Open "myfile.txt" For Input as #1 Line Input #1, aLine Close #1 ' ' This also handles the writing of files Open "myOtherFile.txt" For Append as #2 Print #2, "Hello World" Seek #2, 1 Print #2, "Here at the beginning" Close #2

' ' Using blocks are mapped to with blocks. Using A As Object.Value b = A.Result() End Using

#If Something DoIt() #Else DoSomethingElse() #EndIf