Hello World from cython wiki not working
Question: I'm trying to follow this tutorial from Cython:
<http://docs.cython.org/docs/tutorial.html#the-basics-of-cython> and I'm
having a problem.

The files are very simple. I have a helloworld.pyx:

    
    
    print "Hello World"
    

and a setup.py:

    
    
    from distutils.core import setup
    from distutils.extension import Extension
    from Cython.Distutils import build_ext
    
    setup(
        cmdclass = {'build_ext': build_ext},
        ext_modules = [Extension("helloworld", ["helloworld.pyx"])]
    )
    

and I compile it with the standard command:

    
    
    python setup.py build_ext --inplace
    

I got the following error:

    
    
    running build
    running build_ext
    building 'helloworld' extension
    gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.6 -c helloworld.c -o build/temp.linux-x86_64-2.6/helloworld.o
    helloworld.c:4:20: error: Python.h: No such file or directory
    helloworld.c:5:26: error: structmember.h: No such file or directory
    helloworld.c:34: error: expected specifier-qualifier-list before ‘PyObject’
    helloworld.c:121: error: expected specifier-qualifier-list before ‘PyObject’
    helloworld.c:139: error: expected ‘)’ before ‘*’ token
    helloworld.c:140: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘__pyx_PyInt_AsLongLong’
    helloworld.c:141: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘__pyx_PyInt_AsUnsignedLongLong’
    helloworld.c:142: error: expected ‘)’ before ‘*’ token
    helloworld.c:147: error: expected ‘)’ before ‘*’ token
    helloworld.c:148: error: expected ‘)’ before ‘*’ token
    helloworld.c:149: error: expected ‘)’ before ‘*’ token
    helloworld.c:150: error: expected ‘)’ before ‘*’ token
    helloworld.c:151: error: expected ‘)’ before ‘*’ token
    helloworld.c:152: error: expected ‘)’ before ‘*’ token
    helloworld.c:153: error: expected ‘)’ before ‘*’ token
    helloworld.c:154: error: expected ‘)’ before ‘*’ token
    helloworld.c:155: error: expected ‘)’ before ‘*’ token
    helloworld.c:156: error: expected ‘)’ before ‘*’ token
    helloworld.c:157: error: expected ‘)’ before ‘*’ token
    helloworld.c:172: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘*’ token
    helloworld.c:173: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘*’ token
    helloworld.c:174: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘*’ token
    helloworld.c:181: error: expected ‘)’ before ‘*’ token
    helloworld.c:198: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘*’ token
    helloworld.c:200: error: array type has incomplete element type
    helloworld.c:221: error: ‘__pyx_kp_1’ undeclared here (not in a function)
    helloworld.c:221: warning: excess elements in struct initializer
    helloworld.c:221: warning: (near initialization for ‘__pyx_string_tab[0]’)
    helloworld.c:221: warning: excess elements in struct initializer
    helloworld.c:221: warning: (near initialization for ‘__pyx_string_tab[0]’)
    helloworld.c:221: warning: excess elements in struct initializer
    helloworld.c:221: warning: (near initialization for ‘__pyx_string_tab[0]’)
    helloworld.c:221: warning: excess elements in struct initializer
    helloworld.c:221: warning: (near initialization for ‘__pyx_string_tab[0]’)
    helloworld.c:221: warning: excess elements in struct initializer
    helloworld.c:221: warning: (near initialization for ‘__pyx_string_tab[0]’)
    helloworld.c:221: warning: excess elements in struct initializer
    helloworld.c:221: warning: (near initialization for ‘__pyx_string_tab[0]’)
    helloworld.c:222: warning: excess elements in struct initializer
    helloworld.c:222: warning: (near initialization for ‘__pyx_string_tab[1]’)
    helloworld.c:222: warning: excess elements in struct initializer
    helloworld.c:222: warning: (near initialization for ‘__pyx_string_tab[1]’)
    helloworld.c:222: warning: excess elements in struct initializer
    helloworld.c:222: warning: (near initialization for ‘__pyx_string_tab[1]’)
    helloworld.c:222: warning: excess elements in struct initializer
    helloworld.c:222: warning: (near initialization for ‘__pyx_string_tab[1]’)
    helloworld.c:222: warning: excess elements in struct initializer
    helloworld.c:222: warning: (near initialization for ‘__pyx_string_tab[1]’)
    helloworld.c:222: warning: excess elements in struct initializer
    helloworld.c:222: warning: (near initialization for ‘__pyx_string_tab[1]’)
    helloworld.c:237: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘inithelloworld’
    helloworld.c:238: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘inithelloworld’
    helloworld.c:305: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘*’ token
    helloworld.c:313: error: expected ‘)’ before ‘*’ token
    helloworld.c:379:21: error: compile.h: No such file or directory
    helloworld.c:380:25: error: frameobject.h: No such file or directory
    helloworld.c:381:23: error: traceback.h: No such file or directory
    helloworld.c: In function ‘__Pyx_AddTraceback’:
    helloworld.c:384: error: ‘PyObject’ undeclared (first use in this function)
    helloworld.c:384: error: (Each undeclared identifier is reported only once
    helloworld.c:384: error: for each function it appears in.)
    helloworld.c:384: error: ‘py_srcfile’ undeclared (first use in this function)
    helloworld.c:385: error: ‘py_funcname’ undeclared (first use in this function)
    helloworld.c:386: error: ‘py_globals’ undeclared (first use in this function)
    helloworld.c:387: error: ‘empty_string’ undeclared (first use in this function)
    helloworld.c:388: error: ‘PyCodeObject’ undeclared (first use in this function)
    helloworld.c:388: error: ‘py_code’ undeclared (first use in this function)
    helloworld.c:389: error: ‘PyFrameObject’ undeclared (first use in this function)
    helloworld.c:389: error: ‘py_frame’ undeclared (first use in this function)
    helloworld.c:392: warning: implicit declaration of function ‘PyString_FromString’
    helloworld.c:399: warning: implicit declaration of function ‘PyString_FromFormat’
    helloworld.c:412: warning: implicit declaration of function ‘PyModule_GetDict’
    helloworld.c:412: error: ‘__pyx_m’ undeclared (first use in this function)
    helloworld.c:415: warning: implicit declaration of function ‘PyString_FromStringAndSize’
    helloworld.c:420: warning: implicit declaration of function ‘PyCode_New’
    helloworld.c:429: error: ‘__pyx_empty_tuple’ undeclared (first use in this function)
    helloworld.c:440: warning: implicit declaration of function ‘PyFrame_New’
    helloworld.c:441: warning: implicit declaration of function ‘PyThreadState_GET’
    helloworld.c:448: warning: implicit declaration of function ‘PyTraceBack_Here’
    helloworld.c:450: warning: implicit declaration of function ‘Py_XDECREF’
    helloworld.c: In function ‘__Pyx_InitStrings’:
    helloworld.c:458: error: ‘__Pyx_StringTabEntry’ has no member named ‘p’
    helloworld.c:460: error: ‘__Pyx_StringTabEntry’ has no member named ‘is_unicode’
    helloworld.c:460: error: ‘__Pyx_StringTabEntry’ has no member named ‘is_identifier’
    helloworld.c:461: error: ‘__Pyx_StringTabEntry’ has no member named ‘p’
    helloworld.c:461: warning: implicit declaration of function ‘PyUnicode_DecodeUTF8’
    helloworld.c:461: error: ‘__Pyx_StringTabEntry’ has no member named ‘s’
    helloworld.c:461: error: ‘__Pyx_StringTabEntry’ has no member named ‘n’
    helloworld.c:461: error: ‘NULL’ undeclared (first use in this function)
    helloworld.c:462: error: ‘__Pyx_StringTabEntry’ has no member named ‘intern’
    helloworld.c:463: error: ‘__Pyx_StringTabEntry’ has no member named ‘p’
    helloworld.c:463: warning: implicit declaration of function ‘PyString_InternFromString’
    helloworld.c:463: error: ‘__Pyx_StringTabEntry’ has no member named ‘s’
    helloworld.c:465: error: ‘__Pyx_StringTabEntry’ has no member named ‘p’
    helloworld.c:465: error: ‘__Pyx_StringTabEntry’ has no member named ‘s’
    helloworld.c:465: error: ‘__Pyx_StringTabEntry’ has no member named ‘n’
    helloworld.c:476: error: ‘__Pyx_StringTabEntry’ has no member named ‘p’
    helloworld.c: At top level:
    helloworld.c:485: error: expected ‘)’ before ‘*’ token
    helloworld.c:494: error: expected ‘)’ before ‘*’ token
    helloworld.c:500: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘__pyx_PyInt_AsLongLong’
    helloworld.c:516: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘__pyx_PyInt_AsUnsignedLongLong’
    helloworld.c:538: error: expected ‘)’ before ‘*’ token
    helloworld.c:553: error: expected ‘)’ before ‘*’ token
    helloworld.c:568: error: expected ‘)’ before ‘*’ token
    helloworld.c:583: error: expected ‘)’ before ‘*’ token
    helloworld.c:598: error: expected ‘)’ before ‘*’ token
    helloworld.c:613: error: expected ‘)’ before ‘*’ token
    helloworld.c:628: error: expected ‘)’ before ‘*’ token
    helloworld.c:643: error: expected ‘)’ before ‘*’ token
    helloworld.c:658: error: expected ‘)’ before ‘*’ token
    helloworld.c:673: error: expected ‘)’ before ‘*’ token
    helloworld.c:688: error: expected ‘)’ before ‘*’ token
    error: command 'gcc' failed with exit status 1
    

I have python and cython installed from Ubuntu 9.04 repositories. I can't
figure why the compiler can't find Python.h.

I tried doing:

    
    
    cython helloworld.pyx
    

and then compiling the result manually with gcc:

    
    
    gcc -shared -pthread -fPIC -fwrapv -O2 -Wall -fno-strict-aliasing -I/usr/include/python2.5 -o helloworld.so helloworld.c
    

and got the same exact error message.

Any clues?


Answer: Looks like you're missing some package like `python_dev` or the like -- Debian
and derivatives (including Ubuntu) have long preferred to isolate everything
that could possibly be of "developer"'s use from the parts of a package that
are for "everybody"... a philosophical stance I could debate against (and
_have_ debated against, without much practical success, in mahy fora), but one
that, sadly, can't just be ignored:-(

