treewide: Use argparse.FileType in more places

Convert some scripts to use `argparse.FileType` where the change is relatively
easily doable. This allows better error messages as e.g. missing input files
will be detected during argument parsing. And it also makes writing to stdout
in absence of an explicit argument simpler.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/py/libcamera/gen-py-controls.py

@@ -60,11 +60,13 @@ def main(argv):
     parser = argparse.ArgumentParser()
     parser.add_argument('--mode', '-m', type=str, required=True,
                         help='Mode is either "controls" or "properties"')
-    parser.add_argument('--output', '-o', metavar='file', type=str,
+    parser.add_argument('--output', '-o', metavar='file', default=sys.stdout,
+                        type=argparse.FileType('w', encoding='utf-8'),
                         help='Output file name. Defaults to standard output if not specified.')
-    parser.add_argument('--template', '-t', type=str, required=True,
+    parser.add_argument('--template', '-t', required=True,
+                        type=argparse.FileType('r', encoding='utf-8'),
                         help='Template file name.')
-    parser.add_argument('input', type=str, nargs='+',
+    parser.add_argument('input', type=argparse.FileType('rb'), nargs='+',
                         help='Input file name.')
     args = parser.parse_args(argv[1:])
 
@@ -76,7 +78,7 @@ def main(argv):
     vendors = []
 
     for input in args.input:
-        data = yaml.safe_load(open(input, 'rb').read())
+        data = yaml.safe_load(input)
 
         vendor = data['vendor']
         if vendor != 'libcamera':
@@ -94,15 +96,10 @@ def main(argv):
     }
 
     env = jinja2.Environment()
-    template = env.from_string(open(args.template, 'r', encoding='utf-8').read())
+    template = env.from_string(args.template.read())
     string = template.render(data)
 
-    if args.output:
-        output = open(args.output, 'w', encoding='utf-8')
-        output.write(string)
-        output.close()
-    else:
-        sys.stdout.write(string)
+    args.output.write(string)
 
     return 0
 

src/py/libcamera/gen-py-formats.py

@@ -19,35 +19,23 @@ def generate(formats):
     return {'formats': '\n'.join(fmts)}
 
 
-def fill_template(template, data):
-    with open(template, encoding='utf-8') as f:
-        template = f.read()
-
-    template = string.Template(template)
-    return template.substitute(data)
-
-
 def main(argv):
     parser = argparse.ArgumentParser()
-    parser.add_argument('-o', dest='output', metavar='file', type=str,
+    parser.add_argument('-o', dest='output', metavar='file', default=sys.stdout,
+                        type=argparse.FileType('w', encoding='utf-8'),
                         help='Output file name. Defaults to standard output if not specified.')
-    parser.add_argument('input', type=str,
+    parser.add_argument('input', type=argparse.FileType('rb'),
                         help='Input file name.')
-    parser.add_argument('template', type=str,
+    parser.add_argument('template', type=argparse.FileType('r', encoding='utf-8'),
                         help='Template file name.')
     args = parser.parse_args(argv[1:])
 
-    with open(args.input, 'rb') as f:
-        formats = yaml.safe_load(f)['formats']
+    formats = yaml.safe_load(args.input)['formats']
 
     data = generate(formats)
-    data = fill_template(args.template, data)
+    data = string.Template(args.template.read()).substitute(data)
 
-    if args.output:
-        with open(args.output, 'w', encoding='utf-8') as f:
-            f.write(data)
-    else:
-        sys.stdout.write(data)
+    args.output.write(data)
 
     return 0