To manage Object Storage Service (OSS) buckets, upload and download objects, manage data, or perform image processing, install the OSS SDK for Python. This topic describes the installation process.
Before you begin
Install Python.
OSS SDK for Python requires Python 2.6, 2.7, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, or later.
Note When you install OSS SDK for Python on Windows, make sure that the version of Visual C++ is 15.0 or later.
Run the following command to check the Python version:
python --version
The following response indicates that Python 3.8.2 is installed:
Python 3.8.2
Download OSS SDK for Python
Install python-devel
After you prepare the environment, you must install the python-devel package first.
Note OSS SDK for Python uses the crcmod library for CRC (Cyclic Redundancy Check) calculations. This library has a C extension that provides high performance, but it depends on the Python.h file from the python-devel package. If Python.h is missing when you install the SDK, the C extension for crcmod fails to build. The SDK will still function but will fall back to a pure Python implementation of crcmod. This fallback results in significantly slower performance for operations that require CRC checks, such as object uploads and downloads.
Windows
When you install Python on Windows, the Python.h file is installed together with Python. Therefore, you do not need to install python-devel.
macOS
When you install Python on macOS, the Python.h file is installed together with Python. Therefore, you do not need to install python-devel.
CentOS
Run the following command to install python-devel:
sudo yum install python-devel
RHEL
Run the following command to install python-devel:
sudo yum install python-devel
Fedora
Run the following command to install python-devel:
sudo yum install python-devel
Debian
Run the following command to install python-devel:
sudo apt-get install python-dev
Ubuntu
Run the following command to install python-devel:
sudo apt-get install python-dev
Install OSS SDK for Python
After you install python-devel, you can use one of the following methods to install OSS SDK for Python:
pip
Install pip.
For Python 2.7.9 or later and Python 3.4 or later, pip is installed by default.
Run the following command to install the latest version of OSS SDK for Python:
pip install oss2
Source code
Visit GitHub to download the latest version of OSS SDK for Python package. Decompress the package and check whether the setup.py file exists in the directory.
For more information about how to download an earlier version of OSS SDK for Python, see Historical versions.
Run the following command to install OSS SDK for Python:
python setup.py install
Verify the installation
After installing the SDK, perform the following steps to verify the installation:
Run the following command to enter the Python environment:
python
Run the following command to check the version of OSS SDK for Python:
import oss2
oss2.__version__
The following response indicates that OSS SDK for Python 2.18.3 is installed.
'2.18.3'
FAQ
What do I do if I get a 'No module named _crcfunext' error?
Description
Upload and download operations with the OSS SDK for Python are much slower than with other tools, such as ossutil or other SDKs.
Causes
When you compile the crcmod library, the _crcfunext.so file depends on the Python.h file. The error occurs because the Python.h file does not exist in the system, which causes the _crcfunext.so file to fail to be generated. For more information about crcmod, see crcmod introduction.
Solutions
You can perform the following steps to check whether the crcmod extensions in C are installed:
Run the following command to enter the Python environment:
python
Run the following command to import the C extension module of _crcfunext in the crcmod module:
import crcmod._crcfunext
If the following error message appears, the crcmod extensions in C fail to be installed:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named _crcfunext
Select a solution based on your operating system:
Windows
Download crcmod-1.7.win32-py2.7.msi or a .msi file of a different version.
Note The crcmod library for win32 systems is also compatible with win64 systems.
Install the .msi file and specify the Lib\site-packages directory in the local installation path of Python as the installation path of crcmod. Example: D:\python\Lib\site-packages\.
After the installation is complete, verify the crcmod C extension installation again.
Linux
For Linux, perform the following steps to resolve the issue:
Run the following command to uninstall the crcmod library:
pip uninstall crcmod
Install python-devel. For more information, see Install python-devel.
Run the following command to re-install the crcmod library:
pip install crcmod
If the crcmod library fails to be installed after you perform the preceding steps, uninstall the crcmod library. Then, run the following command to view the details of the installation failure:
pip install crcmod -v
What do I do if I get a "No module named 'Crypto'" error?
Description
Your program fails with a No module named 'Crypto' error.
Causes
This error occurs because the required Crypto module is not installed, or a directory named crypto exists instead of Crypto.
Solutions
Check whether Crypto exists in the local installation path of Python, such as D:\python3.9\Lib\site-packages.
If Crypto does not exist, run the following command:
python -m pip install --upgrade setuptools
If a directory named crypto exists (with a lowercase c), rename it to Crypto and try running your program again.
What do I do if an error message indicating that the command is not an internal or external command is returned?
On Windows, if an error message indicating that the command is not an internal or external command is returned, modify the Path environment variable and add the installation paths of Python and pip to the environment variable. The installation path of pip is the Scripts directory in the installation path of Python. After editing the Path variable, you must open a new command prompt window or restart your computer for the changes to take effect.
What do I do if the SDK installation fails?
If the SDK installation fails, run the following command to uninstall it, then try installing it again.
pip uninstall oss2
How do I upgrade OSS SDK for Python?
Run the following command to upgrade OSS SDK for Python:
pip install --upgrade oss2