Update driver_utils.py

Author: qiuosier

ads/jobs/templates/driver_utils.py

@@ -424,17 +424,19 @@ def conda_unpack(self):
             logger.info("conda-unpack exits with non-zero return code.")
         return self
 
-    def install_pip_requirements(
-        self, req_path: str = os.environ.get(CONST_ENV_PIP_REQ)
-    ):
+    def install_pip_requirements(self, req_path: str = None):
+        if not req_path:
+            req_path = os.environ.get(CONST_ENV_PIP_REQ)
         if not req_path:
             return self
         self.run_command(
             f"pip install -r {req_path}", conda_prefix=self.conda_prefix, check=True
         )
         return self
 
-    def install_pip_packages(self, packages: str = os.environ.get(CONST_ENV_PIP_PKG)):
+    def install_pip_packages(self, packages: str = None):
+        if not packages:
+            packages = os.environ.get(CONST_ENV_PIP_PKG)
         if not packages:
             return self
         self.run_command(