diff --git a/conans/util/env_reader.py b/conans/util/env_reader.py
index 05968a930..cbf46174e 100644
--- a/conans/util/env_reader.py
+++ b/conans/util/env_reader.py
@@ -25,5 +25,7 @@ def get_env(env_key, default=None, environment=None):
         elif isinstance(default, float):
             return float(env_var)
         elif isinstance(default, list):
-            return [var.strip() for var in env_var.split(",")]
+            if env_var.strip():
+                return [var.strip() for var in env_var.split(",")]
+            return []
     return env_var

Unexpected behaviour for 'env_reader.get_env'
Behaviour for `env_reader.get_env` ([link](https://github.com/conan-io/conan/blob/e018e0ff0e7f6addf76cf589f471edc23569939d/conans/util/env_reader.py#L12)):

```python
def get_env(env_key, default=None, environment=None):

    if environment is None:
        environment = os.environ

    env_var = environment.get(env_key, default)
    if env_var != default:
        if isinstance(default, str):
            ...
        elif isinstance(default, list):
            return [var.strip() for var in env_var.split(",")]
    return env_var
```

From my point of view the following is unexpected:

```bash
>>> from conans.util.env_reader import get_env
>>> env = {'CONAN_HOOKS': ''}
>>> get_env('CONAN_HOOKS', default=list(), environment=env)
['']
```

IMO, it should return an empty list.

----

I found this making some trials with hooks, once you deactivate all the hooks you have a `conan.conf` file with an empty section:

```ini
[hooks]

```

and then, when executing any command, it gives me the following warning: `WARN: Hook '.py' not found in /Users/jgsogo/.conan/hooks folder. Please remove hook from conan.conf or include it inside the hooks folder.`

So, if you don't consider the previous behavior as unexpected, then an additional check should be added to the `HookManager` to avoid the warning.

cc/ @conan-io/barbarians 
diff --git a/conans/test/unittests/util/env_reader.py b/conans/test/unittests/util/env_reader.py
new file mode 100644
index 000000000..02f273e1c
--- /dev/null
+++ b/conans/test/unittests/util/env_reader.py
@@ -0,0 +1,28 @@
+# coding=utf-8
+
+import unittest
+from unittest import mock
+
+from conans.util.env_reader import get_env
+
+
+class GetEnvTest(unittest.TestCase):
+    environment = {"EMPTY_LIST": "",
+                   "LIST": "a,b,c,d"}
+
+    def test_environment(self):
+        """ Ensure that we are using os.environment if no argument is passed """
+        with mock.patch("os.environ.get", return_value="zzz"):
+            a = get_env("whatever", default=None)
+        self.assertEqual(a, "zzz")
+
+    def test_list_empty(self):
+        r = get_env("EMPTY_LIST", default=list(), environment=self.environment)
+        self.assertEqual(r, [])
+
+        r = get_env("NON-EXISTING-LIST", default=list(), environment=self.environment)
+        self.assertEqual(r, [])
+
+    def test_list(self):
+        r = get_env("LIST", default=list(), environment=self.environment)
+        self.assertEqual(r, ["a", "b", "c", "d"])

pip install -e .[dev]
parse_log_pytest
requirements.txt
nose nose-cov pytest
apt-get update apt-get install -y gcc cmake
3.6
conans/requirements.txt conans/requirements_server.txt conans/requirements_dev.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
astroid==2.11.7
attrs==22.2.0
beautifulsoup4==4.12.3
bottle==0.12.25
certifi==2021.5.30
charset-normalizer==2.0.12
codecov==2.1.13
colorama==0.4.5
-e git+https://github.com/conan-io/conan.git@ab0870336550b7521da71595c6babf42d5690f7b#egg=conan
cov-core==1.15.0
coverage==4.2
deprecation==2.0.7
dill==0.3.4
distro==1.1.0
fasteners==0.19
future==0.16.0
idna==3.10
importlib-metadata==4.8.3
importlib-resources==5.4.0
iniconfig==1.1.1
isort==5.10.1
lazy-object-proxy==1.7.1
mccabe==0.7.0
mock==1.3.0
node-semver==0.6.1
nose==1.3.7
nose-cov==1.6
packaging==21.3
parameterized==0.8.1
patch==1.16
pbr==6.1.1
platformdirs==2.4.0
pluggy==1.0.0
pluginbase==0.7
py==1.11.0
Pygments==2.14.0
PyJWT==1.7.1
pylint==2.13.9
pyparsing==3.1.4
pytest==7.0.1
PyYAML==3.13
requests==2.27.1
six==1.17.0
soupsieve==2.3.2.post1
tomli==1.2.3
tqdm==4.64.1
typed-ast==1.5.5
typing_extensions==4.1.1
urllib3==1.26.20
waitress==2.0.0
WebOb==1.8.9
WebTest==2.0.35
wrapt==1.16.0
zipp==3.6.0

name: conan
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - astroid==2.11.7
      - attrs==22.2.0
      - beautifulsoup4==4.12.3
      - bottle==0.12.25
      - charset-normalizer==2.0.12
      - codecov==2.1.13
      - colorama==0.4.5
      - cov-core==1.15.0
      - coverage==4.2
      - deprecation==2.0.7
      - dill==0.3.4
      - distro==1.1.0
      - fasteners==0.19
      - future==0.16.0
      - idna==3.10
      - importlib-metadata==4.8.3
      - importlib-resources==5.4.0
      - iniconfig==1.1.1
      - isort==5.10.1
      - lazy-object-proxy==1.7.1
      - mccabe==0.7.0
      - mock==1.3.0
      - node-semver==0.6.1
      - nose==1.3.7
      - nose-cov==1.6
      - packaging==21.3
      - parameterized==0.8.1
      - patch==1.16
      - pbr==6.1.1
      - platformdirs==2.4.0
      - pluggy==1.0.0
      - pluginbase==0.7
      - py==1.11.0
      - pygments==2.14.0
      - pyjwt==1.7.1
      - pylint==2.13.9
      - pyparsing==3.1.4
      - pytest==7.0.1
      - pyyaml==3.13
      - requests==2.27.1
      - six==1.17.0
      - soupsieve==2.3.2.post1
      - tomli==1.2.3
      - tqdm==4.64.1
      - typed-ast==1.5.5
      - typing-extensions==4.1.1
      - urllib3==1.26.20
      - waitress==2.0.0
      - webob==1.8.9
      - webtest==2.0.35
      - wrapt==1.16.0
      - zipp==3.6.0
prefix: /opt/conda/envs/conan

conans/test/unittests/util/env_reader.py::GetEnvTest::test_list_empty
conans/test/unittests/util/env_reader.py::GetEnvTest::test_environment conans/test/unittests/util/env_reader.py::GetEnvTest::test_list
conans/util/env_reader.py
conans/util/env_reader.py