pyupgrade fixes

tljh/conda.py

@@ -72,7 +72,7 @@ def fix_permissions(prefix):
     Run after each install command.
     """
     utils.run_subprocess(
-        ["chown", "-R", "{}:{}".format(os.getuid(), os.getgid()), prefix]
+        ["chown", "-R", f"{os.getuid()}:{os.getgid()}", prefix]
     )
     utils.run_subprocess(["chmod", "-R", "o-w", prefix])
 

tljh/configurer.py

@@ -121,7 +121,7 @@ def load_traefik_api_credentials():
     proxy_secret_path = os.path.join(STATE_DIR, 'traefik-api.secret')
     if not os.path.exists(proxy_secret_path):
         return {}
-    with open(proxy_secret_path, 'r') as f:
+    with open(proxy_secret_path) as f:
         password = f.read()
     return {
         'traefik_api': {

tljh/installer.py

@@ -225,7 +225,7 @@ def ensure_admins(admin_password_list):
     logger.info("Setting up admin users")
     config_path = CONFIG_FILE
     if os.path.exists(config_path):
-        with open(config_path, 'r') as f:
+        with open(config_path) as f:
             config = yaml.load(f)
     else:
         config = {}
@@ -261,7 +261,7 @@ def ensure_jupyterhub_running(times=20):
 
     for i in range(times):
         try:
-            logger.info('Waiting for JupyterHub to come up ({}/{} tries)'.format(i + 1, times))
+            logger.info(f'Waiting for JupyterHub to come up ({i + 1}/{times} tries)')
             # Because we don't care at this level that SSL is valid, we can suppress
             # InsecureRequestWarning for this request.
             with warnings.catch_warnings():
@@ -283,7 +283,7 @@ def ensure_jupyterhub_running(times=20):
             # Everything else should immediately abort
             raise
 
-    raise Exception("Installation failed: JupyterHub did not start in {}s".format(times))
+    raise Exception(f"Installation failed: JupyterHub did not start in {times}s")
 
 
 def ensure_symlinks(prefix):
@@ -388,7 +388,7 @@ def ensure_config_yaml(plugin_manager):
     migrator.migrate_config_files()
 
     if os.path.exists(CONFIG_FILE):
-        with open(CONFIG_FILE, 'r') as f:
+        with open(CONFIG_FILE) as f:
             config = yaml.load(f)
     else:
         config = {}

tljh/traefik.py

@@ -69,7 +69,7 @@ def ensure_traefik_binary(prefix):
     # verify that we got what we expected
     checksum = checksum_file(traefik_bin)
     if checksum != checksums[plat]:
-        raise IOError(f"Checksum failed {traefik_bin}: {checksum} != {checksums[plat]}")
+        raise OSError(f"Checksum failed {traefik_bin}: {checksum} != {checksums[plat]}")
 
 
 def compute_basic_auth(username, password):

tljh/user.py

@@ -34,7 +34,7 @@ def ensure_user(username):
     subprocess.check_call([
         'chmod',
         'o-rwx',
-        expanduser('~{username}'.format(username=username))
+        expanduser(f'~{username}')
     ])
 
     pm = get_plugin_manager()