问题
I am new to Python and Python-Flask and have ran into an error. I am using Ubuntu 18.04.3 LTS and Python 2.7.15+ to build a python-flask web application.
When installing flask-mysqldb I run into an error.
$ pip install flask-mysqldb
The full output:
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Processing ./.cache/pip/wheels/fd/c9/ef/e0e99dfcf898bc040267e36c4a414ff0b22239968a25161012/Flask_MySQLdb-0.2.0-cp27-none-any.whl
Collecting mysqlclient
Using cached https://files.pythonhosted.org/packages/f8/9b/5db9a03e2088a87c26e3e4d4c7f7e8f4c2dbae610f9521cdfac15755a795/mysqlclient-1.4.5.tar.gz
Requirement already satisfied: Flask>=0.10 in ./.local/lib/python2.7/site-packages (from flask-mysqldb) (1.1.1)
Requirement already satisfied: click>=5.1 in ./.local/lib/python2.7/site-packages (from Flask>=0.10->flask-mysqldb) (7.0)
Requirement already satisfied: Werkzeug>=0.15 in ./.local/lib/python2.7/site-packages (from Flask>=0.10->flask-mysqldb) (0.16.0)
Requirement already satisfied: itsdangerous>=0.24 in ./.local/lib/python2.7/site-packages (from Flask>=0.10->flask-mysqldb) (1.1.0)
Requirement already satisfied: Jinja2>=2.10.1 in ./.local/lib/python2.7/site-packages (from Flask>=0.10->flask-mysqldb) (2.10.3)
Requirement already satisfied: MarkupSafe>=0.23 in ./.local/lib/python2.7/site-packages (from Jinja2>=2.10.1->Flask>=0.10->flask-mysqldb) (1.1.1)
Building wheels for collected packages: mysqlclient
Building wheel for mysqlclient (setup.py) ... error
ERROR: Command errored out with exit status 1:
command: /usr/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-Gno8ny/mysqlclient/setup.py'"'"'; __file__='"'"'/tmp/pip-install-Gno8ny/mysqlclient/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /tmp/pip-wheel-OrgtfM --python-tag cp27
cwd: /tmp/pip-install-Gno8ny/mysqlclient/
Complete output (40 lines):
running bdist_wheel
running build
running build_py
creating build
creating build/lib.linux-x86_64-2.7
creating build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/__init__.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/_exceptions.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/compat.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/connections.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/converters.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/cursors.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/release.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/times.py -> build/lib.linux-x86_64-2.7/MySQLdb
creating build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/__init__.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/CLIENT.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/CR.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/ER.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/FIELD_TYPE.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/FLAG.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
running build_ext
building 'MySQLdb._mysql' extension
creating build/temp.linux-x86_64-2.7
creating build/temp.linux-x86_64-2.7/MySQLdb
x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-PPrPZj/python2.7-2.7.15=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -Dversion_info=(1,4,5,'final',0) -D__version__=1.4.5 -I/usr/include/mysql -I/usr/include/python2.7 -c MySQLdb/_mysql.c -o build/temp.linux-x86_64-2.7/MySQLdb/_mysql.o
MySQLdb/_mysql.c: In function ‘_mysql_field_to_python’:
MySQLdb/_mysql.c:1142:33: warning: passing argument 1 of ‘PyInt_FromString’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
return PyInt_FromString(rowitem, NULL, 10);
^~~~~~~
In file included from /usr/include/python2.7/Python.h:89:0,
from MySQLdb/_mysql.c:38:
/usr/include/python2.7/intobject.h:37:24: note: expected ‘char *’ but argument is of type ‘const char *’
PyAPI_FUNC(PyObject *) PyInt_FromString(char*, char**, int);
^~~~~~~~~~~~~~~~
x86_64-linux-gnu-gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-PPrPZj/python2.7-2.7.15=. -fstack-protector-strong -Wformat -Werror=format-security -Wl,-Bsymbolic-functions -Wl,-z,relro -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-PPrPZj/python2.7-2.7.15=. -fstack-protector-strong -Wformat -Werror=format-security build/temp.linux-x86_64-2.7/MySQLdb/_mysql.o -L/usr/lib/x86_64-linux-gnu -lmysqlclient -lpthread -lz -lm -lrt -latomic -lssl -lcrypto -ldl -o build/lib.linux-x86_64-2.7/MySQLdb/_mysql.so
/usr/bin/ld: cannot find -lssl
/usr/bin/ld: cannot find -lcrypto
collect2: error: ld returned 1 exit status
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
----------------------------------------
ERROR: Failed building wheel for mysqlclient
Running setup.py clean for mysqlclient
Failed to build mysqlclient
Installing collected packages: mysqlclient, flask-mysqldb
Running setup.py install for mysqlclient ... error
ERROR: Command errored out with exit status 1:
command: /usr/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-Gno8ny/mysqlclient/setup.py'"'"'; __file__='"'"'/tmp/pip-install-Gno8ny/mysqlclient/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-uh9IqO/install-record.txt --single-version-externally-managed --compile
cwd: /tmp/pip-install-Gno8ny/mysqlclient/
Complete output (40 lines):
running install
running build
running build_py
creating build
creating build/lib.linux-x86_64-2.7
creating build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/__init__.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/_exceptions.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/compat.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/connections.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/converters.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/cursors.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/release.py -> build/lib.linux-x86_64-2.7/MySQLdb
copying MySQLdb/times.py -> build/lib.linux-x86_64-2.7/MySQLdb
creating build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/__init__.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/CLIENT.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/CR.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/ER.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/FIELD_TYPE.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
copying MySQLdb/constants/FLAG.py -> build/lib.linux-x86_64-2.7/MySQLdb/constants
running build_ext
building 'MySQLdb._mysql' extension
creating build/temp.linux-x86_64-2.7
creating build/temp.linux-x86_64-2.7/MySQLdb
x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-PPrPZj/python2.7-2.7.15=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -Dversion_info=(1,4,5,'final',0) -D__version__=1.4.5 -I/usr/include/mysql -I/usr/include/python2.7 -c MySQLdb/_mysql.c -o build/temp.linux-x86_64-2.7/MySQLdb/_mysql.o
MySQLdb/_mysql.c: In function ‘_mysql_field_to_python’:
MySQLdb/_mysql.c:1142:33: warning: passing argument 1 of ‘PyInt_FromString’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
return PyInt_FromString(rowitem, NULL, 10);
^~~~~~~
In file included from /usr/include/python2.7/Python.h:89:0,
from MySQLdb/_mysql.c:38:
/usr/include/python2.7/intobject.h:37:24: note: expected ‘char *’ but argument is of type ‘const char *’
PyAPI_FUNC(PyObject *) PyInt_FromString(char*, char**, int);
^~~~~~~~~~~~~~~~
x86_64-linux-gnu-gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-PPrPZj/python2.7-2.7.15=. -fstack-protector-strong -Wformat -Werror=format-security -Wl,-Bsymbolic-functions -Wl,-z,relro -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-PPrPZj/python2.7-2.7.15=. -fstack-protector-strong -Wformat -Werror=format-security build/temp.linux-x86_64-2.7/MySQLdb/_mysql.o -L/usr/lib/x86_64-linux-gnu -lmysqlclient -lpthread -lz -lm -lrt -latomic -lssl -lcrypto -ldl -o build/lib.linux-x86_64-2.7/MySQLdb/_mysql.so
/usr/bin/ld: cannot find -lssl
/usr/bin/ld: cannot find -lcrypto
collect2: error: ld returned 1 exit status
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
----------------------------------------
ERROR: Command errored out with exit status 1: /usr/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-Gno8ny/mysqlclient/setup.py'"'"'; __file__='"'"'/tmp/pip-install-Gno8ny/mysqlclient/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-uh9IqO/install-record.txt --single-version-externally-managed --compile Check the logs for full command output.`
I have read several other questions and solutions (https://stackoverflow.com/a/51228348/12403455) which suggested using:
mysqlclient‑1.4.5‑cp27‑cp27m‑win_amd64.whl
So I installed this by using:
$ pip install mysqlclient-1.4.5-cp27m-win_amd64.whl
And ran into an error:
Requirement 'mysqlclient‑1.4.5‑cp27‑cp27m‑win_amd64.whl' looks like a filename, but the file does not exist
mysqlclient‑1.4.5‑cp27‑cp27m‑win_amd64.whl is not a valid wheel filename.
I am unsure how to resolve this issue or how to proceed. Any help would be appreciated.
回答1:
You can not use mysqlclient‑1.4.5‑cp27‑cp27m‑win_amd64.whl as you found in other answer, because that is a wheel for Windows and you are on Linux.
The project mysqlclient, which is a dependency of flask-mysqldb, does not distribute wheels for Linux, so you have to build from source code directly (mysqlclient-1.4.5.tar.gz).
Your install likely fails due to missing build dependencies.
As the project landing page has mentioned, install the build dependencies first:
sudo apt-get install python-dev default-libmysqlclient-dev libssl-dev
Then try again to pip install --user flask-mysqldb.
回答2:
I followed instructions from this answer mysql_config not found when installing mysqldb python interface
Just in case I ran
sudo apt-get install mysql-server
later
sudo apt-get install libmysqlclient-dev
and finally
pip3 install flask-mysqldb
and it worked, with Ubuntu 18.04
来源：https://stackoverflow.com/questions/58957474/how-to-install-flask-mysqldb-for-python