René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"cannot use GUI backends inside django request handlers","articleBody":"### Bug summary\r\n\r\nMatplotlib crash Python when trying to create a plot and save it as png\r\n\r\n### Bug report\r\n\r\n\u003e Process:               Python [7315]\r\n\u003e Path:                  /Library/Frameworks/Python.framework/Versions/3.6/Resources/Python.app/Contents/MacOS/Python\r\n\u003e Identifier:            Python\r\n\u003e Version:               3.6.4 (3.6.4)\r\n\u003e Code Type:             X86-64 (Native)\r\n\u003e Parent Process:        bash [6754]\r\n\u003e Responsible:           Python [7315]\r\n\u003e User ID:               501\r\n\u003e \r\n\u003e Date/Time:             2018-04-20 19:30:12.654 +0300\r\n\u003e OS Version:            Mac OS X 10.13.4 (17E199)\r\n\u003e Report Version:        12\r\n\u003e Anonymous UUID:        E1B3F20E-1530-E700-1172-1C41E2D223CF\r\n\u003e \r\n\u003e Sleep/Wake UUID:       CB1FA7B5-1F06-41C5-8BB7-C34FF5EDF3DC\r\n\u003e \r\n\u003e Time Awake Since Boot: 65000 seconds\r\n\u003e Time Since Wake:       5400 seconds\r\n\u003e \r\n\u003e System Integrity Protection: enabled\r\n\u003e \r\n\u003e Crashed Thread:        0  Dispatch queue: com.apple.main-thread\r\n\u003e \r\n\u003e Exception Type:        EXC_CRASH (SIGILL)\r\n\u003e Exception Codes:       0x0000000000000000, 0x0000000000000000\r\n\u003e Exception Note:        EXC_CORPSE_NOTIFY\r\n\u003e \r\n\u003e Termination Signal:    Illegal instruction: 4\r\n\u003e Termination Reason:    Namespace SIGNAL, Code 0x4\r\n\u003e Terminating Process:   Python [7315]\r\n\u003e \r\n\u003e Thread 0 Crashed:: Dispatch queue: com.apple.main-thread\r\n\u003e 0   libsystem_kernel.dylib        \t0x00000001018f14aa __kill + 10\r\n\u003e 1   org.python.python             \t0x00000001008a47bb os_kill + 59\r\n\u003e 2   org.python.python             \t0x00000001007be4c8 _PyCFunction_FastCallDict + 552\r\n\u003e 3   org.python.python             \t0x0000000100847e94 call_function + 612\r\n\u003e 4   org.python.python             \t0x00000001008498a4 _PyEval_EvalFrameDefault + 5604\r\n\u003e 5   org.python.python             \t0x0000000100847bde fast_function + 606\r\n\u003e 6   org.python.python             \t0x0000000100847e7b call_function + 587\r\n\u003e 7   org.python.python             \t0x00000001008498a4 _PyEval_EvalFrameDefault + 5604\r\n\u003e 8   org.python.python             \t0x0000000100847230 _PyEval_EvalCodeWithName + 2720\r\n\u003e 9   org.python.python             \t0x0000000100847a5b fast_function + 219\r\n\u003e 10  org.python.python             \t0x0000000100847e7b call_function + 587\r\n\u003e 11  org.python.python             \t0x00000001008498a4 _PyEval_EvalFrameDefault + 5604\r\n\u003e 12  org.python.python             \t0x0000000100847230 _PyEval_EvalCodeWithName + 2720\r\n\u003e 13  org.python.python             \t0x00000001008480f7 _PyFunction_FastCallDict + 439\r\n\u003e 14  org.python.python             \t0x00000001007627c4 _PyObject_FastCallDict + 356\r\n\u003e 15  org.python.python             \t0x0000000100762e90 _PyObject_Call_Prepend + 208\r\n\u003e 16  org.python.python             \t0x00000001007621b3 PyObject_Call + 99\r\n\u003e 17  org.python.python             \t0x000000010084a326 _PyEval_EvalFrameDefault + 8294\r\n\u003e 18  org.python.python             \t0x0000000100847230 _PyEval_EvalCodeWithName + 2720\r\n\u003e 19  org.python.python             \t0x00000001008480f7 _PyFunction_FastCallDict + 439\r\n\u003e 20  org.python.python             \t0x00000001007627c4 _PyObject_FastCallDict + 356\r\n\u003e 21  org.python.python             \t0x0000000100762e90 _PyObject_Call_Prepend + 208\r\n\u003e 22  org.python.python             \t0x00000001007621b3 PyObject_Call + 99\r\n\u003e 23  org.python.python             \t0x000000010084a326 _PyEval_EvalFrameDefault + 8294\r\n\u003e 24  org.python.python             \t0x0000000100847230 _PyEval_EvalCodeWithName + 2720\r\n\u003e 25  org.python.python             \t0x00000001008480f7 _PyFunction_FastCallDict + 439\r\n\u003e 26  org.python.python             \t0x00000001007627c4 _PyObject_FastCallDict + 356\r\n\u003e 27  org.python.python             \t0x0000000100762e90 _PyObject_Call_Prepend + 208\r\n\u003e 28  org.python.python             \t0x00000001007621b3 PyObject_Call + 99\r\n\u003e 29  org.python.python             \t0x000000010084a326 _PyEval_EvalFrameDefault + 8294\r\n\u003e 30  org.python.python             \t0x0000000100847230 _PyEval_EvalCodeWithName + 2720\r\n\u003e 31  org.python.python             \t0x00000001008480f7 _PyFunction_FastCallDict + 439\r\n\u003e 32  org.python.python             \t0x00000001007627c4 _PyObject_FastCallDict + 356\r\n\u003e 33  org.python.python             \t0x0000000100762e90 _PyObject_Call_Prepend + 208\r\n\u003e 34  org.python.python             \t0x00000001007621b3 PyObject_Call + 99\r\n\u003e 35  org.python.python             \t0x000000010084a326 _PyEval_EvalFrameDefault + 8294\r\n\u003e 36  org.python.python             \t0x0000000100847bde fast_function + 606\r\n\u003e 37  org.python.python             \t0x0000000100847e7b call_function + 587\r\n\u003e 38  org.python.python             \t0x00000001008498a4 _PyEval_EvalFrameDefault + 5604\r\n\u003e 39  org.python.python             \t0x0000000100847bde fast_function + 606\r\n\u003e 40  org.python.python             \t0x0000000100847e7b call_function + 587\r\n\u003e 41  org.python.python             \t0x00000001008498a4 _PyEval_EvalFrameDefault + 5604\r\n\u003e 42  org.python.python             \t0x0000000100847230 _PyEval_EvalCodeWithName + 2720\r\n\u003e 43  org.python.python             \t0x0000000100847a5b fast_function + 219\r\n\u003e 44  org.python.python             \t0x0000000100847e7b call_function + 587\r\n\u003e 45  org.python.python             \t0x00000001008498a4 _PyEval_EvalFrameDefault + 5604\r\n\u003e 46  org.python.python             \t0x0000000100847230 _PyEval_EvalCodeWithName + 2720\r\n\u003e 47  org.python.python             \t0x00000001008473d4 PyEval_EvalCode + 100\r\n\u003e 48  org.python.python             \t0x0000000100883f7e PyRun_FileExFlags + 206\r\n\u003e 49  org.python.python             \t0x000000010088421f PyRun_SimpleFileExFlags + 447\r\n\u003e 50  org.python.python             \t0x000000010089d86a Py_Main + 3914\r\n\u003e 51  org.python.python             \t0x0000000100000dfe 0x100000000 + 3582\r\n\u003e 52  org.python.python             \t0x0000000100000c34 0x100000000 + 3124\r\n\u003e \r\n\u003e Thread 0 crashed with X86 Thread State (64-bit):\r\n\u003e   rax: 0x0000000000000000  rbx: 0x000000010da106c8  rcx: 0x00007fff5bffca78  rdx: 0x0000000000000000\r\n\u003e   rdi: 0x0000000000001c93  rsi: 0x0000000000000004  rbp: 0x00007fff5bffca90  rsp: 0x00007fff5bffca78\r\n\u003e    r8: 0x000000000000006e   r9: 0x0000000000000100  r10: 0x00000001015f8070  r11: 0x0000000000000206\r\n\u003e   r12: 0x0000000000000000  r13: 0x0000000101bbd948  r14: 0x0000000103519e68  r15: 0x00000001008a4780\r\n\u003e   rip: 0x00000001018f14aa  rfl: 0x0000000000000206  cr2: 0x00007fff5df24284\r\n\u003e   \r\n\u003e Logical CPU:     0\r\n\u003e Error Code:      0x02000025\r\n\u003e Trap Number:     133\r\n\u003e \r\n\u003e Model: MacBookPro11,1, BootROM MBP111.0145.B00, 2 processors, Intel Core i5, 2.6 GHz, 8 GB, SMC 2.16f68\r\n\r\n### Code for reproduction\r\n```python\r\nplt.clf()\r\n\tfor stat in all_subscriber_stats:\r\n\t\troaming_minutes_plot_data.append(stat.roaming_minutes)\r\n\t\troaming_gprs_plot_data.append(stat.roaming_gprs)\r\n\t\tinternational_calls_plot_data.append(stat.international_calls)\r\n\t\treporting_months_grid_data.append(\r\n\t\t\tf\"{stat.reporting_month} / {stat.reporting_year}\"\r\n\t\t)\r\n\ty = [\r\n\t\troaming_minutes_plot_data,\r\n\t\troaming_gprs_plot_data,\r\n\t\tinternational_calls_plot_data\r\n\t]\r\n\tplt.stackplot(\r\n\t\treporting_months_grid_data, y, labels=[\r\n\t\t\t'Roaming minutes',\r\n\t\t\t'Roaming GPRS',\r\n\t\t\t'International calls'\r\n\t\t]\r\n\t)\r\n\tplt.legend(loc='best')\r\n\tplt.ylabel('Rub')\r\n\tplt.xlabel(\"Months\")\r\n\tplt.grid(which='major', axis='both')\r\n\r\n\tplt.savefig(\r\n\t\tf'media/{subscriber.user_phone_number}'\r\n\t)\r\n\tsubscriber.spending_statistics_pic = f'{subscriber.user_phone_number}.png'\r\n\tsubscriber.save()\r\n```\r\n\r\n### Actual outcome\r\n\r\nThe crash of Python and Django server\r\n\r\n### Expected outcome\r\n\r\nmatplotlib should generate the *.png file and place it in the folder\r\n\r\n#### Matplotlib version\r\nmatplotlib installd via pip in PyCharm (venv)\r\n\r\n  * **Operating system:** Mac OS X 10.13.4 (17E199)\r\n  * **Matplotlib version:** 2.2.2\r\n  * **Matplotlib backend** (`print(matplotlib.get_backend())`): module://backend_interagg\r\n  * **Python version:** 3.6.4 \r\n  * **Other libraries:** \r\ncycler==0.10.0\r\nDjango==2.0.4\r\nkiwisolver==1.0.1\r\nnumpy==1.14.2\r\npandas==0.22.0\r\nPillow==5.1.0\r\npyparsing==2.2.0\r\npython-dateutil==2.7.2\r\npytz==2018.4\r\nsix==1.11.0\r\n\r\n\r\n## Important Note:\r\nSame code with same dependencies versions working 100%  on Windows10. The problem is only exclusive to Mac and began when I started using matplotlib in my code\r\n","author":{"url":"https://github.com/SimonOsipov","@type":"Person","name":"SimonOsipov"},"datePublished":"2018-04-20T16:48:50.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":18},"url":"https://github.com/11094/matplotlib/issues/11094"}