diff --git a/.github/workflows/test_pip.yml b/.github/workflows/test_pip.yml
index 4376c42..3ff8c13 100644
--- a/.github/workflows/test_pip.yml
+++ b/.github/workflows/test_pip.yml
@@ -8,9 +8,10 @@ jobs:
   Test_run:
     runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
         os: [ubuntu-18.04, macOS-latest, windows-2019]
-        python-version: [3.5, 3.6, 3.7, 3.8]
+        python-version: [3.5, 3.6, 3.7, 3.8, 3.9]
     steps:
     - name: git pull
       uses: actions/checkout@v1
diff --git a/.github/workflows/test_run.yml b/.github/workflows/test_run.yml
index ef6158f..2b3a285 100644
--- a/.github/workflows/test_run.yml
+++ b/.github/workflows/test_run.yml
@@ -6,9 +6,10 @@ jobs:
   Test_run:
     runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
         os: [ubuntu-18.04, macOS-latest, windows-2019]
-        python-version: [3.5, 3.6, 3.7, 3.8]
+        python-version: [3.5, 3.6, 3.7, 3.8, 3.9]
     steps:
     - name: git pull
       uses: actions/checkout@v1
diff --git a/README.md b/README.md
index 3100b87..7274cb7 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ Read/Write metadata of digital image, including [EXIF](https://en.wikipedia.org/
 ## Features
 
 - Base on C++ API of [Exiv2](https://www.exiv2.org/index.html) and invoke it through [pybind11](https://github.com/pybind/pybind11).
-- Supports running on Linux, MacOS and Windows, with Python3(64bit, including `3.5` `3.6` `3.7` `3.8`).
+- Supports running on Linux, MacOS and Windows, with Python3(64bit, including `3.5` `3.6` `3.7` `3.8` `3.9`).
   If you want to run pyexiv2 on another platform, please compile it yourself. See [lib](https://github.com/LeoHsiao1/pyexiv2/blob/master/pyexiv2/lib/README.md)
 - [Supports various metadata](https://www.exiv2.org/metadata.html)
 - [Supports various image formats](https://dev.exiv2.org/projects/exiv2/wiki/Supported_image_formats)
diff --git a/docs/Tutorial-cn.md b/docs/Tutorial-cn.md
index 7a502c9..7f88a16 100644
--- a/docs/Tutorial-cn.md
+++ b/docs/Tutorial-cn.md
@@ -13,9 +13,9 @@ class Image:
     def read_xmp(self, encoding='utf-8') -> dict
     def read_raw_xmp(self, encoding='utf-8') -> str
 
-    def modify_exif(self, dict_, encoding='utf-8')
-    def modify_iptc(self, dict_, encoding='utf-8')
-    def modify_xmp(self, dict_, encoding='utf-8')
+    def modify_exif(self, data: dict, encoding='utf-8')
+    def modify_iptc(self, data: dict, encoding='utf-8')
+    def modify_xmp(self, data: dict, encoding='utf-8')
 
     def clear_exif(self)
     def clear_iptc(self)
@@ -27,22 +27,22 @@ class ImageData(Image):
     def __init__(self, data: bytes)
     def get_bytes(self) -> bytes
 
-set_log_level()
+set_log_level(level=2)
 ```
 
 ## 类 Image
 
 - 类 `Image` 用于根据文件路径打开图片。例如：
     ```py
-    >>> from pyexiv2 import Image
-    >>> img = Image(r'.\pyexiv2\tests\1.jpg')
+    >>> import pyexiv2
+    >>> img = pyexiv2.Image(r'.\pyexiv2\tests\1.jpg')
     >>> data = img.read_exif()
     >>> img.close()
     ```
 - 当你处理完图片之后，请记得调用 `img.close()` ，以释放用于存储图片数据的内存。不调用该方法会导致内存泄漏，但不会锁定文件描述符。
 - 通过 `with` 关键字打开图片时，它会自动关闭图片。例如：
     ```py
-    with Image(r'.\pyexiv2\tests\1.jpg') as img:
+    with pyexiv2.Image(r'.\pyexiv2\tests\1.jpg') as img:
         ims.read_exif()
     ```
 
@@ -50,8 +50,6 @@ set_log_level()
 
 - 示例:
     ```py
-    >>> from pyexiv2 import Image
-    >>> img = Image(r'.\pyexiv2\tests\1.jpg')
     >>> img.read_exif()
     {'Exif.Image.DateTime': '2019:06:23 19:45:17', 'Exif.Image.Artist': 'TEST', 'Exif.Image.Rating': '4', ...}
     >>> img.read_iptc()
@@ -63,12 +61,12 @@ set_log_level()
 - pyexiv2 支持包含 Unicode 字符的图片路径、元数据。大部分函数都有一个默认参数：`encoding='utf-8'`。
   如果你因为图片路径、元数据包含非 ASCII 码字符而遇到错误，请尝试更换编码。例如：
     ```python
-    img = Image(path, encoding='utf-8')
-    img = Image(path, encoding='GBK')
-    img = Image(path, encoding='ISO-8859-1')
+    img = pyexiv2.Image(path, encoding='utf-8')
+    img = pyexiv2.Image(path, encoding='GBK')
+    img = pyexiv2.Image(path, encoding='ISO-8859-1')
     ```
    另一个例子：中国地区的 Windows 电脑通常用 GBK 编码文件路径，因此它们不能被 utf-8 解码。
-- 使用`Image.read_*()`是安全的。这些方法永远不会影响图片文件。（md5不变）
+- 使用 `Image.read_*()` 是安全的。这些方法永远不会影响图片文件（md5不变）。
 - 如果 XMP 元数据包含 `\v` 或 `\f`，它将被空格 ` ` 代替。
 - 元数据的读取速度与元数据的数量成反比，不管图片的大小如何。
 
@@ -76,7 +74,6 @@ set_log_level()
 
 - 示例:
     ```py
-    >>> img = Image(r'.\pyexiv2\tests\1.jpg')
     >>> # 准备要修改的XMP数据
     >>> dict1 = {'Xmp.xmp.CreateDate': '2019-06-23T19:45:17.834',   # 这将覆盖该标签的原始值，如果不存在该标签则将其添加
     ...          'Xmp.xmp.Rating': ''}                              # 赋值一个空字符串会删除该标签
@@ -124,20 +121,20 @@ set_log_level()
 - 读取的示例：
     ```py
     with open(r'.\pyexiv2\tests\1.jpg', 'rb') as f:
-        with ImageData(f.read()) as img:
+        with pyexiv2.ImageData(f.read()) as img:
             data = img.read_exif()
     ```
 - 修改的示例：
     ```py
     with open(r'.\pyexiv2\tests\1.jpg', 'rb+') as f:
-        with ImageData(f.read()) as img:
+        with pyexiv2.ImageData(f.read()) as img:
             changes = {'Iptc.Application2.ObjectName': 'test'}
             img.modify_iptc(changes)
             f.seek(0)
             # 获取图片的字节数据并保存到文件中
             f.write(img.get_bytes())
         f.seek(0)
-        with ImageData(f.read()) as img:
+        with pyexiv2.ImageData(f.read()) as img:
             result = img.read_iptc()
     ```
 
@@ -171,8 +168,6 @@ set_log_level()
 - `error` 日志会被转换成异常并抛出，其它日志则会被打印到 stdout 。
 - 调用函数 `pyexiv2.set_log_level()` 可以设置处理日志的级别。例如：
     ```py
-    >>> import pyexiv2
-    >>> img = pyexiv2.Image(r'.\pyexiv2\tests\1.jpg')
     >>> img.modify_xmp({'Xmp.xmpMM.History': 'type="Seq"'})
     RuntimeError: XMP Toolkit error 102: Indexing applied to non-array
     Failed to encode XMP metadata.
diff --git a/docs/Tutorial.md b/docs/Tutorial.md
index 9222b5e..6b9239f 100644
--- a/docs/Tutorial.md
+++ b/docs/Tutorial.md
@@ -13,9 +13,9 @@ class Image:
     def read_xmp(self, encoding='utf-8') -> dict
     def read_raw_xmp(self, encoding='utf-8') -> str
 
-    def modify_exif(self, dict_, encoding='utf-8')
-    def modify_iptc(self, dict_, encoding='utf-8')
-    def modify_xmp(self, dict_, encoding='utf-8')
+    def modify_exif(self, data: dict, encoding='utf-8')
+    def modify_iptc(self, data: dict, encoding='utf-8')
+    def modify_xmp(self, data: dict, encoding='utf-8')
 
     def clear_exif(self)
     def clear_iptc(self)
@@ -27,22 +27,22 @@ class ImageData(Image):
     def __init__(self, data: bytes)
     def get_bytes(self) -> bytes
 
-set_log_level()
+set_log_level(level=2)
 ```
 
 ## class Image
 
 - Class `Image` is used to open an image based on the file path. For example:
     ```py
-    >>> from pyexiv2 import Image
-    >>> img = Image(r'.\pyexiv2\tests\1.jpg')
+    >>> import pyexiv2
+    >>> img = pyexiv2.Image(r'.\pyexiv2\tests\1.jpg')
     >>> data = img.read_exif()
     >>> img.close()
     ```
 - When you're done with the image, remember to call `img.close()` to free the memory for storing image data. Not calling this method causes a memory leak, but it doesn't lock the file descriptor.
 - Opening an image by keyword `with` will close the image automatically. For example:
     ```py
-    with Image(r'.\pyexiv2\tests\1.jpg') as img:
+    with pyexiv2.Image(r'.\pyexiv2\tests\1.jpg') as img:
         data = ims.read_exif()
     ```
 
@@ -50,7 +50,6 @@ set_log_level()
 
 - Sample:
     ```py
-    >>> img = Image(r'.\pyexiv2\tests\1.jpg')
     >>> img.read_exif()
     {'Exif.Image.DateTime': '2019:06:23 19:45:17', 'Exif.Image.Artist': 'TEST', 'Exif.Image.Rating': '4', ...}
     >>> img.read_iptc()
@@ -67,7 +66,7 @@ set_log_level()
     img = Image(path, encoding='ISO-8859-1')
     ```
   Another example: Windows computers in China usually encoded file paths by GBK, so they cannot be decoded by utf-8.
-- It is safe to use `Image.read_*()`. These methods never affect image files. (md5 unchanged)
+- It is safe to use `Image.read_*()`. These methods never affect image files (md5 unchanged).
 - If the XMP metadata contains `\v` or `\f`, it will be replaced with space ` `.
 - The speed of reading metadata is inversely proportional to the amount of metadata, regardless of the size of the image.
 
@@ -75,7 +74,6 @@ set_log_level()
 
 - Sample:
     ```py
-    >>> img = Image(r'.\pyexiv2\tests\1.jpg')
     >>> # Prepare the XMP data you want to modify
     >>> dict1 = {'Xmp.xmp.CreateDate': '2019-06-23T19:45:17.834',   # This will overwrite its original value, or add it if it doesn't exist
     ...          'Xmp.xmp.Rating': ''}                              # Set an empty str explicitly to delete the datum
@@ -123,20 +121,20 @@ set_log_level()
 - Example of reading:
     ```py
     with open(r'.\pyexiv2\tests\1.jpg', 'rb') as f:
-        with ImageData(f.read()) as img:
+        with pyexiv2.ImageData(f.read()) as img:
             data = img.read_exif()
     ```
 - Example of modifing:
     ```py
     with open(r'.\pyexiv2\tests\1.jpg', 'rb+') as f:
-        with ImageData(f.read()) as img:
+        with pyexiv2.ImageData(f.read()) as img:
             changes = {'Iptc.Application2.ObjectName': 'test'}
             img.modify_iptc(changes)
             f.seek(0)
             # Get the bytes data of the image and save it to the file
             f.write(img.get_bytes())
         f.seek(0)
-        with ImageData(f.read()) as img:
+        with pyexiv2.ImageData(f.read()) as img:
             result = img.read_iptc()
     ```
 
@@ -170,13 +168,10 @@ set_log_level()
 - The `error` log will be converted to an exception and thrown. Other logs will be printed to stdout.
 - Call the function `pyexiv2.set_log_level()` to set the level of handling logs. For example:
     ```py
-    >>> import pyexiv2
-    >>> img = pyexiv2.Image(r'.\pyexiv2\tests\1.jpg')
-    >>> img.modify_xmp({'Xmp.xmpMM.History': 'type="Seq"'})
+    >>> img.modify_xmp({'Xmp.xmpMM.History': 'type="Seq"'}) # An error that was not caught is displayed
     RuntimeError: XMP Toolkit error 102: Indexing applied to non-array
     Failed to encode XMP metadata.
 
     >>> pyexiv2.set_log_level(4)
-    >>> img.modify_xmp({'Xmp.xmpMM.History': 'type="Seq"'})
-    >>> img.close()
+    >>> img.modify_xmp({'Xmp.xmpMM.History': 'type="Seq"'}) # No error displayed
     ```
diff --git a/pyexiv2/core.py b/pyexiv2/core.py
index 553a9fb..c9841b7 100644
--- a/pyexiv2/core.py
+++ b/pyexiv2/core.py
@@ -25,9 +25,9 @@ def close(self):
         """ Free the memory for storing image data. """
         self.img.close_image()
         
-        # Disable all members
+        # Disable all methods and properties
         def closed_warning():
-            raise RuntimeError('Do not operate on the closed image.')
+            raise RuntimeError('The image has been closed, so it is not allowed to operate.')
         for attr in dir(self):
             if not attr.startswith('__'):
                 if callable(getattr(self, attr)):
diff --git a/pyexiv2/lib/README.md b/pyexiv2/lib/README.md
index d2b3e3a..90beccb 100644
--- a/pyexiv2/lib/README.md
+++ b/pyexiv2/lib/README.md
@@ -23,65 +23,66 @@
 - The current release version of Exiv2 is `0.27.2`.
 - It is not necessary to compile all versions of exiv2api.cpp and save them to the git repository, except when release a new version.
 
-## Compile steps on Darwin
+## Compile steps on Linux
 
 1. Download the release version of Exiv2, unpack it.
-    - Darwin : <https://www.exiv2.org/archive.html>
+    - Linux64 : <https://www.exiv2.org/archive.html>
     - For example:
         ```sh
-        cd /Users/leo/Documents/
-        curl -O https://www.exiv2.org/builds/exiv2-0.27.2-Darwin.tar.gz
-        tar -zxvf exiv2-0.27.2-Darwin.tar.gz
+        cd /root/
+        curl -O https://www.exiv2.org/builds/exiv2-0.27.2-Linux64.tar.gz
+        tar -zxvf exiv2-0.27.2-Linux64.tar.gz
         ```
 
 2. Prepare the environment:
     ```sh
-    EXIV2_DIR=/Users/leo/Documents/exiv2-0.27.2-Darwin
-    LIB_DIR=/Users/leo/Documents/pyexiv2/pyexiv2/lib/
-    cp ${EXIV2_DIR}/lib/libexiv2.0.27.2.dylib ${LIB_DIR}/libexiv2.dylib
+    EXIV2_DIR=/root/exiv2-0.27.2-Linux64   # According to your download location
+    LIB_DIR=/root/pyexiv2/pyexiv2/lib/
+    cp ${EXIV2_DIR}/lib/libexiv2.so.0.27.2 $LIB_DIR/libexiv2.so
     ```
 
 3. Set up the python interpreter. For example:
     ```sh
     py_version=8
+    # docker run -it --rm --name python3.$py_version -e "py_version=$py_version" -e "EXIV2_DIR=$EXIV2_DIR" -e "LIB_DIR=$LIB_DIR" -v /root:/root python:3.$py_version-buster sh
     python3.$py_version -m pip install pybind11
     ```
 
 4. Compile:
     ```sh
     cd $LIB_DIR
-    g++ exiv2api.cpp -o py3${py_version}-darwin/exiv2api.so -O3 -Wall -std=c++11 -shared -fPIC `python3.$py_version -m pybind11 --includes` -I ${EXIV2_DIR}/include -L ${EXIV2_DIR}/lib -l exiv2 -undefined dynamic_lookup
+    g++ exiv2api.cpp -o py3${py_version}-linux/exiv2api.so -O3 -Wall -std=c++11 -shared -fPIC `python3.$py_version -m pybind11 --includes` -I ${EXIV2_DIR}/include -L ${EXIV2_DIR}/lib -l exiv2
     ```
 
-## Compile steps on Linux
+## Compile steps on Darwin
 
 1. Download the release version of Exiv2, unpack it.
-    - Linux64 : <https://www.exiv2.org/archive.html>
+    - Darwin : <https://www.exiv2.org/archive.html>
     - For example:
         ```sh
-        cd /root/pyexiv2/
-        curl -O https://www.exiv2.org/builds/exiv2-0.27.2-Linux64.tar.gz
-        tar -zxvf exiv2-0.27.2-Linux64.tar.gz
+        cd /Users/leo/Documents/
+        curl -O https://www.exiv2.org/builds/exiv2-0.27.2-Darwin.tar.gz
+        tar -zxvf exiv2-0.27.2-Darwin.tar.gz
         ```
 
 2. Prepare the environment:
     ```sh
-    EXIV2_DIR=/root/pyexiv2/exiv2-0.27.2-Linux64   # According to your download location
-    LIB_DIR=/root/pyexiv2/pyexiv2/lib/
-    cp ${EXIV2_DIR}/lib/libexiv2.so.0.27.2 $LIB_DIR/libexiv2.so
+    EXIV2_DIR=/Users/leo/Documents/exiv2-0.27.2-Darwin
+    LIB_DIR=/Users/leo/Documents/pyexiv2/pyexiv2/lib/
+    cp ${EXIV2_DIR}/lib/libexiv2.0.27.2.dylib ${EXIV2_DIR}/lib/libexiv2.dylib
+    cp ${EXIV2_DIR}/lib/libexiv2.0.27.2.dylib ${LIB_DIR}/libexiv2.dylib
     ```
 
 3. Set up the python interpreter. For example:
     ```sh
     py_version=8
-    docker run -it --rm --name python3.$py_version -e "py_version=$py_version" -e "EXIV2_DIR=$EXIV2_DIR" -e "LIB_DIR=$LIB_DIR" -v /root/pyexiv2:/root/pyexiv2 python:3.$py_version bash
     python3.$py_version -m pip install pybind11
     ```
 
 4. Compile:
     ```sh
     cd $LIB_DIR
-    g++ exiv2api.cpp -o py3${py_version}-linux/exiv2api.so -O3 -Wall -std=c++11 -shared -fPIC `python3.$py_version -m pybind11 --includes` -I ${EXIV2_DIR}/include -L ${EXIV2_DIR}/lib -l exiv2
+    g++ exiv2api.cpp -o py3${py_version}-darwin/exiv2api.so -O3 -Wall -std=c++11 -shared -fPIC `python3.$py_version -m pybind11 --includes` -I ${EXIV2_DIR}/include -L ${EXIV2_DIR}/lib -l exiv2 -undefined dynamic_lookup
     ```
 
 ## Compile steps on Windows
@@ -102,7 +103,8 @@
 4. Compile:
     ```batch
     set py_version=8
-    cl /MD /LD exiv2api.cpp /EHsc -I %EXIV2_DIR%\include -I C:\Users\Leo\AppData\Local\Programs\Python\Python3%py_version%\include /link %EXIV2_DIR%\lib\exiv2.lib C:\Users\Leo\AppData\Local\Programs\Python\Python3%py_version%\libs\python3%py_version%.lib /OUT:py3%py_version%-win\exiv2api.pyd
+    set py_home=C:\Users\Leo\AppData\Local\Programs\Python\Python3%py_version%
+    cl /MD /LD exiv2api.cpp /EHsc -I %EXIV2_DIR%\include -I %py_home%\include -I %py_home%\Lib\site-packages\pybind11\include /link %EXIV2_DIR%\lib\exiv2.lib %py_home%\libs\python3%py_version%.lib /OUT:py3%py_version%-win\exiv2api.pyd
     del exiv2api.exp exiv2api.obj exiv2api.lib
     ```
-    Modify the path here according to your installation location.
+    - Modify the path here according to your installation location.
diff --git a/pyexiv2/lib/__init__.py b/pyexiv2/lib/__init__.py
index 5446283..8949696 100644
--- a/pyexiv2/lib/__init__.py
+++ b/pyexiv2/lib/__init__.py
@@ -4,12 +4,14 @@
 import platform
 
 
-# Check the Python interpreter
 if platform.architecture()[0] != '64bit':
     raise RuntimeError('pyexiv2 can only run on 64-bit python3 interpreter.')
+
+# Check the Python interpreter
 py_version = platform.python_version()[:3]
-if py_version not in ['3.5', '3.6', '3.7', '3.8']:
-    raise RuntimeError('pyexiv2 only supports these Python versions: 3.5, 3.6, 3.7, 3.8 , but your version is {} .'.format(py_version))
+expected_py_version = ['3.5', '3.6', '3.7', '3.8', '3.9']
+if py_version not in expected_py_version:
+    raise RuntimeError('pyexiv2 only supports these Python versions: {} . But your version is {} .'.format(expected_py_version, py_version))
 
 lib_dir = os.path.dirname(__file__)
 
diff --git a/pyexiv2/lib/py39-darwin/__init__.py b/pyexiv2/lib/py39-darwin/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/pyexiv2/lib/py39-darwin/exiv2api.so b/pyexiv2/lib/py39-darwin/exiv2api.so
new file mode 100644
index 0000000..1112045
Binary files /dev/null and b/pyexiv2/lib/py39-darwin/exiv2api.so differ
diff --git a/pyexiv2/lib/py39-linux/__init__.py b/pyexiv2/lib/py39-linux/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/pyexiv2/lib/py39-linux/exiv2api.so b/pyexiv2/lib/py39-linux/exiv2api.so
new file mode 100644
index 0000000..8add36f
Binary files /dev/null and b/pyexiv2/lib/py39-linux/exiv2api.so differ
diff --git a/pyexiv2/lib/py39-win/__init__.py b/pyexiv2/lib/py39-win/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/pyexiv2/lib/py39-win/exiv2api.pyd b/pyexiv2/lib/py39-win/exiv2api.pyd
new file mode 100644
index 0000000..532fff3
Binary files /dev/null and b/pyexiv2/lib/py39-win/exiv2api.pyd differ
diff --git a/setup.py b/setup.py
index ee71883..248607e 100644
--- a/setup.py
+++ b/setup.py
@@ -6,7 +6,7 @@
 
 setuptools.setup(
     name='pyexiv2',
-    version='2.3.1',
+    version='2.3.2',
     author='LeoHsiao',
     author_email='leohsiao@foxmail.com',
     description='Read/Write metadata of digital image, including EXIF, IPTC, XMP.',
@@ -29,6 +29,7 @@
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
     ],
 )