What s the bad magic number error

Question

What s the  Bad magic number  ImportError in python  and how do I fix it   The only thing I can find online suggests this is caused by compiling a  py -   pyc file and then trying to use it with the wrong version of python  In my case  however  the file seems to import fine some times but not others  and I m not sure why   The information python s providing in the traceback isn t particularly helpful  which is why I was asking here      but here it is in case it helps   Traceback  most recent call last     File  run py   line 7  in  lt module gt      from Normalization import Normalizer

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I just faced the same issue with Fedora26 where many tools such as dnf were broken due to bad magic number for six  For an unknown reason i ve got a file  usr bin six pyc  with the unexpected magic number  Deleting this file fix the problem

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In my case  I ve git clone a lib which had an interpreter of      usr bin env python   While python was leading to Python2 7 even though my main code was running with python3 6     it still created a   pyc file for 2 7 version      I can say that this error probably is a result of a mix between 2 7  amp  3  versions  this is why cleanup   in any way you can think of that you re using   - will help here       don t forget to adjust those Python2x code -  python 3

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The magic number comes from UNIX-type systems where the first few bytes of a file held a marker indicating the file type   Python puts a similar marker into its pyc files when it creates them   Then the python interpreter makes sure this number is correct when loading it   Anything that damages this magic number will cause your problem  This includes editing the pyc file or trying to run a pyc from a different version of python  usually later  than your interpreter   If they are your pyc files  just delete them and let the interpreter re-compile the py files  On UNIX type systems  that could be something as simple as   rm   pyc   or   find   -name    pyc  -delete   If they are not yours  you ll have to either get the py files for re-compilation  or an interpreter that can run the pyc files with that particular magic value   One thing that might be causing the intermittent nature  The pyc that s causing the problem may only be imported under certain conditions  It s highly unlikely it would import sometimes  You should check the actual full stack trace when the import fails   As an aside  the first word of all my 2 5 1 r251 54863  pyc files is 62131  2 6 1 r261 67517  is 62161  The list of all magic numbers can be found in Python import c  reproduced here for completeness  current as at the time the answer was posted  it may have changed since then    1 5    20121 1 5 1  20121 1 5 2  20121 1 6    50428 2 0    50823 2 0 1  50823 2 1    60202 2 1 1  60202 2 1 2  60202 2 2    60717 2 3a0  62011 2 3a0  62021 2 3a0  62011 2 4a0  62041 2 4a3  62051 2 4b1  62061 2 5a0  62071 2 5a0  62081 2 5a0  62091 2 5a0  62092 2 5b3  62101 2 5b3  62111 2 5c1  62121 2 5c2  62131 2 6a0  62151 2 6a1  62161 2 7a0  62171

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This is much more efficent than above   find  directory-of- pyc-files  -name    pyc  -print0   xargs -0 rm -rf   where  directory-of- pyc-files  is the directory that contains the compiled python files

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So i had the same error  importError bad magic number  This was on windows 10 This error was because i installed mysql-connector So i had to  pip uninstall mysql-comnector pip uninstall mysql-connector-python pip install mysql-connector-python

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Loading a python3 generated   pyc file with python2 also causes this error

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I had a strange case of Bad Magic Number error using a very old  1 5 2  implementation  I generated a  pyo file and that triggered the error  Bizarrely  the problem was solved by changing the name of the module  The offending name was sms py  If I generated an sms pyo from that module  Bad Magic Number error was the result  When I changed the name to smst py  the error went away  I checked back and forth to see if sms py somehow interfered with any other module with the same name but I could not find any name collision  Even though the source of this problem remained a mistery for me  I recommend trying a module name change

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The magic number comes from UNIX-type systems where the first few bytes of a file held a marker indicating the file type   Python puts a similar marker into its pyc files when it creates them   Then the python interpreter makes sure this number is correct when loading it   Anything that damages this magic number will cause your problem  This includes editing the pyc file or trying to run a pyc from a different version of python  usually later  than your interpreter   If they are your pyc files  just delete them and let the interpreter re-compile the py files  On UNIX type systems  that could be something as simple as   rm   pyc   or   find   -name    pyc  -delete   If they are not yours  you ll have to either get the py files for re-compilation  or an interpreter that can run the pyc files with that particular magic value   One thing that might be causing the intermittent nature  The pyc that s causing the problem may only be imported under certain conditions  It s highly unlikely it would import sometimes  You should check the actual full stack trace when the import fails   As an aside  the first word of all my 2 5 1 r251 54863  pyc files is 62131  2 6 1 r261 67517  is 62161  The list of all magic numbers can be found in Python import c  reproduced here for completeness  current as at the time the answer was posted  it may have changed since then    1 5    20121 1 5 1  20121 1 5 2  20121 1 6    50428 2 0    50823 2 0 1  50823 2 1    60202 2 1 1  60202 2 1 2  60202 2 2    60717 2 3a0  62011 2 3a0  62021 2 3a0  62011 2 4a0  62041 2 4a3  62051 2 4b1  62061 2 5a0  62071 2 5a0  62081 2 5a0  62091 2 5a0  62092 2 5b3  62101 2 5b3  62111 2 5c1  62121 2 5c2  62131 2 6a0  62151 2 6a1  62161 2 7a0  62171

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Take the pyc file to a windows machine  Use any Hex editor to open this pyc file  I used freeware  HexEdit   Now read hex value of first two bytes  In my case  these were 03 f3   Open calc and convert its display mode to Programmer  Scientific in XP  to see Hex and Decimal conversion  Select  Hex  from Radio button  Enter values as second byte first and then the first byte i e f303 Now click on  Dec   Decimal  radio button  The value displayed is one which is correspond to the magic number aka version of python    So  considering the table provided in earlier reply   1 5    20121    4E99  so files would have first byte as 99 and second as 4e 1 6    50428    C4FC  so files would have first byte as fc and second as c4

User · Answer

I had a strange case of Bad Magic Number error using a very old  1 5 2  implementation  I generated a  pyo file and that triggered the error  Bizarrely  the problem was solved by changing the name of the module  The offending name was sms py  If I generated an sms pyo from that module  Bad Magic Number error was the result  When I changed the name to smst py  the error went away  I checked back and forth to see if sms py somehow interfered with any other module with the same name but I could not find any name collision  Even though the source of this problem remained a mistery for me  I recommend trying a module name change

User · Answer

This can also be due to missing   init   py file from the directory  Say if you create a new directory in django for seperating the unit tests into multiple files and place them in one directory then you also have to create the   init   py file beside all the other files in new created test directory  otherwise it can give error like  Traceback  most recent call last     File  C  Users USERNAME AppData Local Programs Python Python35 Lib unittest loader py  line 153  in loadTestsFromName     module     import   module name  ImportError  bad magic number in  APPNAME tests   b  x03 xf3 r n

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This can also happen if you have the wrong python27 dll file  in case of Windows   to solve this just re-install  or extract  python with the exact corresponding dll version  I had a similar experience

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You will need to run this command in every path you have in your environment     gt  gt  gt  import sys  gt  gt  gt  sys path        usr lib python36 zip     usr lib python3 6     usr lib python3 6 lib-dynload     usr local lib python3 6 dist-packages     source code src python     usr lib python3 dist-packages      Then run the command in every directory here  find  usr lib python3 6  -name    pyc  -delete find  usr local lib python3 6 dist-packages -name    pyc  -delete   etc

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In my case it was not  pyc but old binary  mo translation files after I renamed my own module  so inside this module folder I had to run  find   -name    po -execdir sh -c  msgfmt   0  -o  basename  0  po  mo             please do backup and try to fix  pyc files first

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Deleting all  pyc files will fix  Bad Magic Number  error   find   -name    pyc  -delete

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Don t delete them    Until            Find a version on your git  svn or copy folder that works    Delete them and then recover all  pyc    That s work for me

User · Answer

Loading a python3 generated   pyc file with python2 also causes this error

User · Answer

In my case it was not  pyc but old binary  mo translation files after I renamed my own module  so inside this module folder I had to run  find   -name    po -execdir sh -c  msgfmt   0  -o  basename  0  po  mo             please do backup and try to fix  pyc files first

User · Answer

Bad magic number  error also happens if you have manually named your file with an extension  pyc

User · Answer

This can also happen if you have the wrong python27 dll file  in case of Windows   to solve this just re-install  or extract  python with the exact corresponding dll version  I had a similar experience

User · Answer

In my case  I ve git clone a lib which had an interpreter of      usr bin env python   While python was leading to Python2 7 even though my main code was running with python3 6     it still created a   pyc file for 2 7 version      I can say that this error probably is a result of a mix between 2 7  amp  3  versions  this is why cleanup   in any way you can think of that you re using   - will help here       don t forget to adjust those Python2x code -  python 3

User · Answer

This is much more efficent than above   find  directory-of- pyc-files  -name    pyc  -print0   xargs -0 rm -rf   where  directory-of- pyc-files  is the directory that contains the compiled python files

User · Answer

The magic number comes from UNIX-type systems where the first few bytes of a file held a marker indicating the file type   Python puts a similar marker into its pyc files when it creates them   Then the python interpreter makes sure this number is correct when loading it   Anything that damages this magic number will cause your problem  This includes editing the pyc file or trying to run a pyc from a different version of python  usually later  than your interpreter   If they are your pyc files  just delete them and let the interpreter re-compile the py files  On UNIX type systems  that could be something as simple as   rm   pyc   or   find   -name    pyc  -delete   If they are not yours  you ll have to either get the py files for re-compilation  or an interpreter that can run the pyc files with that particular magic value   One thing that might be causing the intermittent nature  The pyc that s causing the problem may only be imported under certain conditions  It s highly unlikely it would import sometimes  You should check the actual full stack trace when the import fails   As an aside  the first word of all my 2 5 1 r251 54863  pyc files is 62131  2 6 1 r261 67517  is 62161  The list of all magic numbers can be found in Python import c  reproduced here for completeness  current as at the time the answer was posted  it may have changed since then    1 5    20121 1 5 1  20121 1 5 2  20121 1 6    50428 2 0    50823 2 0 1  50823 2 1    60202 2 1 1  60202 2 1 2  60202 2 2    60717 2 3a0  62011 2 3a0  62021 2 3a0  62011 2 4a0  62041 2 4a3  62051 2 4b1  62061 2 5a0  62071 2 5a0  62081 2 5a0  62091 2 5a0  62092 2 5b3  62101 2 5b3  62111 2 5c1  62121 2 5c2  62131 2 6a0  62151 2 6a1  62161 2 7a0  62171

User · Answer

Take the pyc file to a windows machine  Use any Hex editor to open this pyc file  I used freeware  HexEdit   Now read hex value of first two bytes  In my case  these were 03 f3   Open calc and convert its display mode to Programmer  Scientific in XP  to see Hex and Decimal conversion  Select  Hex  from Radio button  Enter values as second byte first and then the first byte i e f303 Now click on  Dec   Decimal  radio button  The value displayed is one which is correspond to the magic number aka version of python    So  considering the table provided in earlier reply   1 5    20121    4E99  so files would have first byte as 99 and second as 4e 1 6    50428    C4FC  so files would have first byte as fc and second as c4

User · Answer

Don t delete them    Until            Find a version on your git  svn or copy folder that works    Delete them and then recover all  pyc    That s work for me

User · Answer

The magic number comes from UNIX-type systems where the first few bytes of a file held a marker indicating the file type   Python puts a similar marker into its pyc files when it creates them   Then the python interpreter makes sure this number is correct when loading it   Anything that damages this magic number will cause your problem  This includes editing the pyc file or trying to run a pyc from a different version of python  usually later  than your interpreter   If they are your pyc files  just delete them and let the interpreter re-compile the py files  On UNIX type systems  that could be something as simple as   rm   pyc   or   find   -name    pyc  -delete   If they are not yours  you ll have to either get the py files for re-compilation  or an interpreter that can run the pyc files with that particular magic value   One thing that might be causing the intermittent nature  The pyc that s causing the problem may only be imported under certain conditions  It s highly unlikely it would import sometimes  You should check the actual full stack trace when the import fails   As an aside  the first word of all my 2 5 1 r251 54863  pyc files is 62131  2 6 1 r261 67517  is 62161  The list of all magic numbers can be found in Python import c  reproduced here for completeness  current as at the time the answer was posted  it may have changed since then    1 5    20121 1 5 1  20121 1 5 2  20121 1 6    50428 2 0    50823 2 0 1  50823 2 1    60202 2 1 1  60202 2 1 2  60202 2 2    60717 2 3a0  62011 2 3a0  62021 2 3a0  62011 2 4a0  62041 2 4a3  62051 2 4b1  62061 2 5a0  62071 2 5a0  62081 2 5a0  62091 2 5a0  62092 2 5b3  62101 2 5b3  62111 2 5c1  62121 2 5c2  62131 2 6a0  62151 2 6a1  62161 2 7a0  62171

User · Answer

I just faced the same issue with Fedora26 where many tools such as dnf were broken due to bad magic number for six  For an unknown reason i ve got a file  usr bin six pyc  with the unexpected magic number  Deleting this file fix the problem

User · Answer

Deleting all  pyc files will fix  Bad Magic Number  error   find   -name    pyc  -delete

User · Answer

You will need to run this command in every path you have in your environment     gt  gt  gt  import sys  gt  gt  gt  sys path        usr lib python36 zip     usr lib python3 6     usr lib python3 6 lib-dynload     usr local lib python3 6 dist-packages     source code src python     usr lib python3 dist-packages      Then run the command in every directory here  find  usr lib python3 6  -name    pyc  -delete find  usr local lib python3 6 dist-packages -name    pyc  -delete   etc

User · Answer

Bad magic number  error also happens if you have manually named your file with an extension  pyc

User · Answer

So i had the same error  importError bad magic number  This was on windows 10 This error was because i installed mysql-connector So i had to  pip uninstall mysql-comnector pip uninstall mysql-connector-python pip install mysql-connector-python

User · Answer

This can also be due to missing   init   py file from the directory  Say if you create a new directory in django for seperating the unit tests into multiple files and place them in one directory then you also have to create the   init   py file beside all the other files in new created test directory  otherwise it can give error like  Traceback  most recent call last     File  C  Users USERNAME AppData Local Programs Python Python35 Lib unittest loader py  line 153  in loadTestsFromName     module     import   module name  ImportError  bad magic number in  APPNAME tests   b  x03 xf3 r n

[python] What's the bad magic number error?

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