Modernize the code base with f-strings (#1068)

httpie/utils.py

@@ -62,7 +62,7 @@ def humanize_bytes(n, precision=2):
             break
 
     # noinspection PyUnboundLocalVariable
-    return '%.*f %s' % (precision, n / factor, suffix)
+    return f'{n / factor:.{precision}f} {suffix}'
 
 
 class ExplicitNullAuth(requests.auth.AuthBase):
@@ -85,7 +85,7 @@ def get_content_type(filename):
     if mime:
         content_type = mime
         if encoding:
-            content_type = '%s; charset=%s' % (mime, encoding)
+            content_type = f'{mime}; charset={encoding}'
         return content_type