first try

src/invoice_generator/html_generator.py

@@ -0,0 +1,38 @@
+from pathlib import Path
+from jinja2 import FileSystemLoader, TemplateNotFound, Environment
+
+from xhtml2pdf import pisa
+
+
+class HtmlTemplate:
+    def __init__(self, templates):
+        self.template_name = 'invoice.html'
+        if not Path(templates).exists():
+            raise FileNotFoundError(f'Inivalid path to template files: {templates}')
+        self.templates = templates
+
+    def prepare_template(self, invoice_data, envelope_data):
+        try:
+            loader = FileSystemLoader(self.templates)
+            env = Environment(loader=loader)
+
+            template = env.get_template(self.template_name)
+            return template.render(invoice=invoice_data, envelope=envelope_data)
+        except TemplateNotFound:
+            raise FileNotFoundError(f'Could not find template file: {self.template_name}')
+
+    @staticmethod
+    def convert_html_to_pdf(source_html, output_filename):
+        # open output file for writing (truncated binary)
+        result_file = open(output_filename, "w+b")
+
+        # convert HTML to PDF
+        pisa_status = pisa.CreatePDF(
+            source_html,  # the HTML to convert
+            dest=result_file)  # file handle to recieve result
+
+        # close output file
+        result_file.close()  # close output file
+
+        # return False on success and True on errors
+        return pisa_status.err

src/main.py

@@ -0,0 +1,104 @@
+import argparse
+import yaml
+from pathlib import Path
+
+from invoice_generator import html_generator
+
+
+class DataObject:
+    def __init__(self, **kwargs):
+        for key, value in kwargs.items():
+            setattr(self, key, value)
+
+
+def parse_yaml_file(file_path):
+    with open(file_path, 'r') as file:
+        return yaml.safe_load(file)
+
+
+def check_file(file_path):
+    try_out_extensions = ['.yaml', '.yml']
+
+    for ext in try_out_extensions:
+        if file_path.exists():
+            return file_path
+        file_path = file_path.with_suffix(ext)
+    return None
+
+
+# Utility function
+
+
+def main():
+    print('Simple invoice generator for freelancers and small businesses by Torsten Ueberschar')
+    print()
+    parser = argparse.ArgumentParser(description='Read invoice and envelope data from yaml file')
+    parser.add_argument('-b', '--base', type=str, required=True, help='base directory for invoice and envelope files')
+    parser.add_argument('-i', '--invoice', type=str, required=True, help='Invoice file name')
+    parser.add_argument('-e', '--envelope', type=str, required=False, default='envelope.yaml',
+                        help='Envelope file name')
+    parser.add_argument('-t', '--template', type=str, required=False, default='template',
+                        help='directory for template files')
+
+    args = parser.parse_args()
+
+    invoice_file = args.invoice
+    envelope_file = args.envelope
+
+    print(f'Searching for invoice files in: {args.base}')
+
+    invoice_file = Path(args.base) / invoice_file
+    envelope_file = Path(args.base) / envelope_file
+
+    invoice_file = check_file(invoice_file)
+    envelope_file = check_file(envelope_file)
+
+    print(f'Found invoice file: {invoice_file}')
+    print(f'Found envelope file: {envelope_file}')
+
+    if invoice_file is None:
+        print('Error: No invoice file found')
+        return
+    if envelope_file is None:
+        print('Error: No envelope file found')
+        return
+
+    try:
+        invoice = parse_yaml_file(invoice_file)
+        envelope = parse_yaml_file(envelope_file)
+
+        print('Invoice data:')
+        print(invoice)
+
+        print(envelope)
+
+        print('Envelope data:')
+        envelope_data = DataObject(**envelope)
+        print(envelope_data.__dict__)
+
+        print('Invoice data:')
+        invoice_data = DataObject(**invoice)
+        print(invoice_data.__dict__)
+
+    except FileNotFoundError as e:
+        print(f'Error: {e}')
+        return
+    except yaml.YAMLError as e:
+        print(f'Error: {e}')
+        return
+    except Exception as e:
+        print(f'Error: {e}')
+        return
+
+    generator = html_generator.HtmlTemplate(args.template)
+    template = generator.prepare_template(invoice_data, envelope_data)
+
+    try:
+        html_generator.HtmlTemplate.convert_html_to_pdf(template, 'invoice.pdf')
+    except Exception as e:
+        print(f'Error: {e}')
+        return
+
+
+if __name__ == "__main__":
+    main()