python: Convert more "".format to Python 3.6 f-strings.

Generated by pyupgrade --py36-plus --keep-percent-format.

Now including %d, %i, %u, and multi-line strings.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

tools/droplets/create.py

@@ -118,7 +118,7 @@ def set_user_data(username: str, userkey_dicts: List[Dict[str, Any]]) -> str:
     server_repo_setup = setup_repo.format(username, "zulip")
     python_api_repo_setup = setup_repo.format(username, "python-zulip-api")
 
-    cloudconf = """\
+    cloudconf = f"""\
 #!/bin/bash
 
 {setup_zulipdev_ssh_keys}
@@ -130,10 +130,7 @@ su -c '{server_repo_setup}' zulipdev
 su -c '{python_api_repo_setup}' zulipdev
 su -c 'git config --global core.editor nano' zulipdev
 su -c 'git config --global pull.rebase true' zulipdev
-""".format(setup_root_ssh_keys=setup_root_ssh_keys,
-           setup_zulipdev_ssh_keys=setup_zulipdev_ssh_keys,
-           hostname_setup=hostname_setup,
-           server_repo_setup=server_repo_setup, python_api_repo_setup=python_api_repo_setup)
+"""
     print("...returning cloud-config data.")
     return cloudconf
 

tools/lib/html_branches.py

@@ -181,9 +181,9 @@ def build_id_dict(templates: List[str]) -> (Dict[str, List[str]]):
         try:
             list_tags = tokenize(text)
         except FormattedException as e:
-            raise Exception('''
-                fn: {}
-                {}'''.format(fn, e))
+            raise Exception(f'''
+                fn: {fn}
+                {e}''')
 
         for tag in list_tags:
             info = get_tag_info(tag)

tools/lib/template_parser.py

@@ -213,9 +213,9 @@ def validate(fn: Optional[str] = None, text: Optional[str] = None, check_indent:
     try:
         tokens = tokenize(text)
     except FormattedException as e:
-        raise TemplateParserException('''
-            fn: {}
-            {}'''.format(fn, e))
+        raise TemplateParserException(f'''
+            fn: {fn}
+            {e}''')
 
     class State:
         def __init__(self, func: Callable[[Token], None]) -> None: