VBA to Python Syntax Mapping

Data Types

VBA is statically typed with explicit declarations. Python is dynamically typed, but type hints provide equivalent documentation. The converter preserves Dim declarations as comments for traceability.

Variable Declarations

Dim count As Integer
Dim name As String
Dim total As Double
Dim isValid As Boolean

# Dim count As Integer
# Dim name As String
# Dim total As Double
# Dim isValid As Boolean
count: int = 0
name: str = ""
total: float = 0.0
is_valid: bool = False

The converter keeps Dim statements as comments so you can trace the original declarations during code review.

Operators

Control Flow

The converter handles all standard VBA control flow structures. Each is mapped to its Python equivalent while preserving the original branching logic.

If / ElseIf / Else

If score >= 90 Then
    grade = "A"
ElseIf score >= 80 Then
    grade = "B"
Else
    grade = "C"
End If

if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
else:
    grade = "C"

For / Next

For i = 1 To 10
    total = total + i
Next i

For j = 10 To 1 Step -1
    Debug.Print j
Next j

for i in range(1, 10 + 1):
    total = total + i

for j in range(10, 1 - 1, -1):
    print(j)

Note the + 1 adjustment: VBA For loops are inclusive on both ends, while Python's range() excludes the upper bound. See the loops guide for more detail.

Select Case

Select Case rating
    Case "A"
        bonus = 1000
    Case "B", "C"
        bonus = 500
    Case Is >= "D"
        bonus = 0
    Case Else
        bonus = 0
End Select

if rating == "A":
    bonus = 1000
elif rating in ("B", "C"):
    bonus = 500
elif rating >= "D":
    bonus = 0
else:
    bonus = 0

Do While / Do Until

Do While row <= lastRow
    total = total + Cells(row, 1).Value
    row = row + 1
Loop

Do Until found = True
    ' search logic
Loop

while row <= lastRow:
    total = total + ws.cell(row=row, column=1).value
    row = row + 1

while not (found == True):
    # search logic
    pass

For Each

For Each cell In Range("A1:A10")
    If cell.Value <> "" Then
        count = count + 1
    End If
Next cell

for cell in ws["A1:A10"]:
    if cell.value != "":
        count = count + 1

Built-in Function Mapping

The converter maps 53 VBA functions to Python equivalents. Functions with a helper generate a small utility function in the output to handle VBA-specific edge cases like 1-based string indexing. Functions with an import add the appropriate Python module import automatically.

String Functions

Type Conversion & Checking

Math Functions

Date/Time Functions

Array & I/O Functions

See the string functions guide for detailed examples and edge cases for each string helper.

Constants

Excel Object Model (openpyxl)

The converter translates VBA Excel objects to openpyxl equivalents. Every converted Sub or Function receives a ws (worksheet) parameter automatically.

Subs and Functions

Sub ProcessData()
    ' Sub with no return value
End Sub

Function AddTax(price As Double) As Double
    AddTax = price * 1.1
End Function

def ProcessData(ws):
    # Sub with no return value
    pass

def AddTax(ws, price):
    return price * 1.1

The converter automatically adds a ws parameter for worksheet access and converts FunctionName = value return patterns to return value.

Error Handling

On Error GoTo ErrHandler
    ' risky code
    Exit Sub
ErrHandler:
    MsgBox Err.Description

try:
    # risky code
except Exception as e:
    print(str(e))

The converter flags On Error statements for manual review because VBA error handling is structurally different from Python exceptions. See the GoTo and error handling guide for refactoring strategies.

Frequently Asked Questions

Related Guides

• Complete Migration Guide — Step-by-step process for migrating a full VBA project to Python.
• Excel VBA to Python with openpyxl — Deep dive into Range, Cells, and worksheet operations.
• VBA String Functions in Python — Trim, Left, Mid, InStr, Replace with edge cases and examples.
• VBA Loops to Python — For, For Each, Do While, Do Until with the range() gotcha.