| name | template-processing |
| description | Process templates with placeholder substitution and conditional sections |
Template Processing: Placeholders and Conditionals
Overview
When filling document templates, you often need to:
- Replace placeholders like
{{PLACEHOLDER}} with actual data
- Handle conditional sections (show/hide content based on data)
- Clean up formatting markers
This skill covers patterns for template processing in both text and document contexts.
Placeholder Patterns
Basic Placeholders
{{CANDIDATE_FULL_NAME}}
{{POSITION}}
{{START_DATE}}
{{BASE_SALARY}}
Parsing from JSON
import json
with open('employee_data.json', 'r') as f:
data = json.load(f)
name = data['CANDIDATE_FULL_NAME']
position = data['POSITION']
Conditional Section Pattern
Template Format
{{IF_CONDITION_NAME}}
Content to show if CONDITION_NAME is "Yes"
{{END_IF_CONDITION_NAME}}
Processing Conditionals
def process_conditional_section(text, condition_key, condition_value):
"""Remove conditional markers based on condition value"""
start_marker = f'{{{{IF_{condition_key}}}}}'
end_marker = f'{{{{END_IF_{condition_key}}}}}'
start_idx = text.find(start_marker)
end_idx = text.find(end_marker)
if start_idx == -1 or end_idx == -1:
return text
before = text[:start_idx]
content = text[start_idx + len(start_marker):end_idx]
after = text[end_idx + len(end_marker):]
if condition_value.lower() == 'yes':
return before + content + after
else:
return before + after
Workflow for Template Processing
Step 1: Load Data
import json
from docx import Document
with open('employee_data.json', 'r') as f:
data = json.load(f)
doc = Document('template.docx')
Step 2: Replace Basic Placeholders
def replace_placeholders(doc, data):
"""Replace all {{PLACEHOLDER}} with data values"""
for para in doc.paragraphs:
para_text = para.text
for key, value in data.items():
placeholder = f'{{{{{key}}}}}'
para_text = para_text.replace(placeholder, str(value))
if para_text != para.text:
for run in para.runs:
run.text = ''
para.text = para_text
for table in doc.tables:
for row in table.rows:
for cell in row.cells:
cell_text = cell.text
for key, value in data.items():
placeholder = f'{{{{{key}}}}}'
cell_text = cell_text.replace(placeholder, str(value))
if cell_text != cell.text:
for para in cell.paragraphs:
for run in para.runs:
run.text = ''
para.text = cell_text
cell_text = cell.text
Step 3: Handle Conditionals
def process_conditionals(doc, data):
"""Process {{IF_*}}...{{END_IF_*}} sections"""
for para in doc.paragraphs:
para_text = para.text
import re
pattern = r'{{\s*IF_(\w+)\s*}}(.*?){{\s*END_IF_\1\s*}}'
def replace_conditional(match):
condition_key = match.group(1)
content = match.group(2)
condition_value = data.get(condition_key, 'No')
if condition_value == 'Yes':
return content.strip()
else:
return ''
new_text = re.sub(pattern, replace_conditional, para_text, flags=re.DOTALL)
if new_text != para_text:
for run in para.runs:
run.text = ''
para.text = new_text
Important Considerations
-
Text Fragmentation in Word: Placeholders might be split across multiple runs. Always work at the paragraph level (para.text) not individual run level.
-
Order of Operations:
- First handle conditionals (remove sections)
- Then replace placeholders
-
Multiline Content: When using regex for conditionals, use re.DOTALL flag to match across newlines
-
Data Type Conversion: Convert all data values to strings when replacing:
placeholder_value = str(data[key])
-
Preserve Formatting: The simple approach loses formatting. For preserving formatting:
- Replace in individual runs while checking full paragraph
- Or use a more sophisticated run-level replacement with formatting preservation
Complete Example
import json
import re
from docx import Document
def fill_offer_letter(template_path, data_path, output_path):
with open(data_path) as f:
data = json.load(f)
doc = Document(template_path)
for para in doc.paragraphs:
text = para.text
pattern = r'{{\s*IF_(\w+)\s*}}(.*?){{\s*END_IF_\1\s*}}'
def replace_cond(m):
key = m.group(1)
content = m.group(2)
return content.strip() if data.get(key) == 'Yes' else ''
text = re.sub(pattern, replace_cond, text, flags=re.DOTALL)
for key, value in data.items():
text = text.replace(f'{{{{{key}}}}}', str(value))
if text != para.text:
for run in para.runs:
run.text = ''
para.text = text
for table in doc.tables:
for row in table.rows:
for cell in row.cells:
para cell.paragraphs:
text = para.text
pattern =
text = re.sub(pattern, replace_cond, text, flags=re.DOTALL)
key, value data.items():
text = text.replace(, (value))
text != para.text:
run para.runs:
run.text =
para.text = text
doc.save(output_path)