Merge pull request #6 from yguarata/master

Adding function to apply stamps in PDF.

README.md

@@ -36,9 +36,12 @@ Return the number of pages for a given PDF
 
 ### `replace_page`
 Replace a page in a PDF (pdf_path) by the PDF pointed by pdf_to_insert_path.
- - pdf_path is the PDF that will have its page replaced.
- - page_number is the number of the page in pdf_path to be replaced. It is 1-based.
- - pdf_to_insert_path is the PDF that will be inserted at the old page.
+ - `pdf_path` is the PDF that will have its page replaced.
+ - `page_number` is the number of the page in pdf_path to be replaced. It is 1-based.
+ - `pdf_to_insert_path` is the PDF that will be inserted at the old page.
+
+### `stamp`
+Applies a stamp (from `stamp_pdf_path`) to the PDF file in `pdf_path`. If no `output_pdf_path` is provided, it returns a temporary file with the result PDF.
 
 
 ## Example

pypdftk.py

@@ -131,10 +131,10 @@ def gen_xfdf(datas={}):
     return out_file
 
 def replace_page(pdf_path, page_number, pdf_to_insert_path):
-    """
+    '''
     Replace a page in a PDF (pdf_path) by the PDF pointed by pdf_to_insert_path.
     page_number is the number of the page in pdf_path to be replaced. It is 1-based.
-    """
+    '''
     A = 'A=' + pdf_path
     B = 'B=' + pdf_to_insert_path
     lower_bound = 'A1-' + str(page_number - 1)
@@ -143,4 +143,14 @@ def replace_page(pdf_path, page_number, pdf_to_insert_path):
     args = (PDFTK_PATH, A, B, 'cat', lower_bound, 'B', upper_bound, 'output', output_temp)
     run_command(args)
     shutil.copy(output_temp, pdf_path)
-    os.remove(output_temp)
+    os.remove(output_temp)
+
+def stamp(pdf_path, stamp_pdf_path, output_pdf_path=None):
+    '''
+    Applies a stamp (from stamp_pdf_path) to the PDF file in pdf_path. Useful for watermark purposes.
+    If not output_pdf_path is provided, it returns a temporary file with the result PDF.
+    '''
+    output = output_pdf_path or tempfile.mktemp(suffix='.pdf')
+    args = [PDFTK_PATH, pdf_path, 'multistamp', stamp_pdf_path, 'output', output]
+    run_command(args)
+    return output