resample: use argparse instead of sys.argv

scripts/resample.py

@@ -1,5 +1,15 @@
 #!/usr/bin/env python
 from amodem.sampling import resample
+import argparse
 import sys
 
-resample(src=sys.stdin, dst=sys.stdout, df=float(sys.argv[1]))
+
+def main():
+    p = argparse.ArgumentParser()
+    p.add_argument('df', type=float)
+    args = p.parse_args()
+
+    resample(src=sys.stdin, dst=sys.stdout, df=args.df)
+
+if __name__ == '__main__':
+    main()