pyinvoice: check if weasyprint is available before trying to use it

src/schwarz/pyinvoice/cli.py

@@ -18,7 +18,7 @@
 from .check import check_invoice, MetaInfo
 from .config import parse_config
 from .parser import InvoiceParser
-from .pdf_generator import generate_pdf
+from .pdf_generator import generate_pdf, is_weasyprint_available
 
 
 __all__ = ['cli_main']
@@ -74,5 +74,9 @@ def cli_main():
         if found_error:
             return
 
+    if not is_weasyprint_available():
+        print('"weasyprint" not found, please install the weasyprint package.')
+        return
+
     generate_pdf(invoice, invoice_cfg, target_path=pdf_path, with_logo=with_logo)
 

src/schwarz/pyinvoice/pdf_generator.py

@@ -8,7 +8,14 @@
 import jinja2
 
 
-__all__ = ['generate_pdf']
+__all__ = ['generate_pdf', 'is_weasyprint_available']
+
+def is_weasyprint_available():
+    try:
+        subprocess.run(['weasyprint', '--version'], capture_output=True, shell=False)
+    except FileNotFoundError:
+        return False
+    return True
 
 def generate_pdf(invoice, invoice_cfg, target_path, *, with_logo=False):
     template_path = Path(invoice_cfg['template'])