Creating a Batch File Renaming Utility for Engineering Documents

The Document Naming Challenge

Engineering projects generate thousands of files: drawings, calculations, reports, correspondence, submittals, and shop drawings. Every company has a naming convention — project number, discipline code, document type, revision number — but manually renaming files to match is tedious and error-prone. When a project has 500 drawings that arrived from a subconsultant with their naming convention, someone has to rename every single file. That someone should be a script, not a person.

Defining Renaming Patterns

Support three common renaming operations:

• Find and replace: Replace one text pattern with another across all selected files. Change "PRELIM" to "FINAL" in 200 filenames at once.
• Sequential numbering: Add or change a sequence number. Rename "Drawing.pdf" to "PRJ001-S-001.pdf" through "PRJ001-S-200.pdf".
• Pattern-based restructuring: Extract parts of the existing filename and rearrange them. Convert "BeamDesign_Floor3_Rev2.xlsx" to "PRJ001-STR-BD-F03-R02.xlsx" using regex capture groups.

Preview Before Executing

This is the most critical feature. Display the current filename alongside the proposed new filename in a two-column table. Let the user review every change before committing. Highlight any conflicts — two files that would end up with the same name, or names that exceed the Windows path length limit. Never rename without preview. One wrong pattern applied to 500 files creates a mess that takes longer to fix than the original manual renaming.

Implementing Undo

Save a rename log — a JSON file mapping new names back to original names. If something goes wrong, the undo function reads the log and reverses every rename operation. Store the log in the same directory as the renamed files, timestamped, so multiple rename operations each have their own recovery point.

Building the Interface

Use a folder selection dialog to choose the target directory. Add filter options for file types (PDF only, Excel only, all files). Display the file list in a scrollable table with checkboxes so users can exclude specific files from the operation. Place the pattern input and rename button prominently above the preview table.

Practical Engineering Use Cases

• Renaming drawing sets received from subconsultants to match your project naming convention
• Adding revision numbers to an entire submittal package
• Standardizing file names before uploading to a document management system
• Stripping unnecessary prefixes or suffixes added by scanning software
• Converting file names from one language to another for international projects

Sample Code

# Python: batch rename engineering documents
import os
import re

def batch_rename(folder, pattern, replacement):
    # pattern uses regex; replacement can include \1, \2 groups
    renamed = 0
    for name in sorted(os.listdir(folder)):
        new_name = re.sub(pattern, replacement, name)
        if new_name != name:
            src = os.path.join(folder, name)
            dst = os.path.join(folder, new_name)
            os.rename(src, dst)
            print(f'{name}  ->  {new_name}')
            renamed += 1
    print(f'Renamed {renamed} files.')

# Example: add project prefix and fix numbering
# "DWG-001.pdf" -> "PRJ-2024-DWG-001.pdf"
batch_rename(
    'C:/Projects/Drawings',
    r'^(DWG-\d+)',
    'PRJ-2024-\\1'
)