1. 使用f2py用fortain给python写扩展

numpy许多算法实现是使用Fortran,f2py就是numpy中用于将Fortran代码编译为python可以使用的动态链接库的工具.

本文主要介绍如何使用f2py编译Fortran代码,使python可以调用.

1.1. 是否有必要用Fortran写扩展

这个要看应用的领域,Fortran是专为计算设计的编程语言,多维数组是内置的数据类型,可以说在向量计算矩阵计算上它有天然的优势,而且语法相比C语言更加接近python,也没有复杂的语法和底层概念,用它写扩展可以专注于算法.因此如果一个模块完全是做计算的,那它就很适合用这门语言写扩展.

但同时它的劣势也就在于太过小众,如果一个人已经回C/C++,甚至不用是精通,他往往也没有动力再学一门新语言.同时Fortran除了写计算逻辑优秀以外几乎可以说一无是处.也没什么现代的编程技巧,因此除非是用作写算法模块,否则确实不值得专门学个这.

那为啥还要写这一节?

因为科学计算是python最重要的应用领域,几乎没有之一;数学家,物理学家往往都不关心怎么编程,只关心算法本身.如果是年级大点的数学家,物理学家,几乎都学过Fortran,而年轻的可能没学过,但Fortran好上手的特性非常适合作为第一门高性能计算编程语言.因此这个需求和这个用户群体非常契合.这就值得介绍一下了.

1.2. 简单fortain语法

相对比价现代,支持面又比较广的是fortran95标准.其基本特点是:

• 完整的结构化和模块化
• 矩阵运算支持
• 简单的子程序接口,方便传递矩阵
• 功能强大而简单的Namelist输入输出
• 对并行计算提供特别支持
• 编译代码执行效率高
• 内置函数较少

1.2.1. 基本规则

• 大小写不敏感
• 自由格式
• &为换行连写
• !为注释语句
• 程序中任何地方用stop可推出程序
• 建议每个域(program、module、function、 subrouting)第一行都写implicit none

1.3. 使用f2py编译fortran的pyton扩展

此处给出一个简单的求平方和的例子用于演示demo.f95:

subroutine sum_of_square(x, y, n)         implicit none       integer, intent(in) :: n         integer :: i       real(kind=8), intent(in) :: x(n)         real(kind=8), intent(out) :: y         y = 0       do i=1, n               y = y + x(i)**2       end do   end 

使用命令f2py -c -m <module_name> file_path就可以很简单的将其编译为python模块

!f2py -c -m demo demo.f95 --quiet 

In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpqavw1pmi/src.macosx-10.7-x86_64-3.6/demomodule.c:16: In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpqavw1pmi/src.macosx-10.7-x86_64-3.6/fortranobject.h:13: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/arrayobject.h:4: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarrayobject.h:18: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarraytypes.h:1816: /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/npy_1_7_deprecated_api.h:15:2: warning: "Using deprecated NumPy API, disable it by "          "#defining NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION" [-W#warnings] #warning "Using deprecated NumPy API, disable it by " \  ^ /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpqavw1pmi/src.macosx-10.7-x86_64-3.6/demomodule.c:109:12: warning: unused function 'f2py_size' [-Wunused-function] static int f2py_size(PyArrayObject* var, ...)            ^ 2 warnings generated. In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpqavw1pmi/src.macosx-10.7-x86_64-3.6/fortranobject.c:2: In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpqavw1pmi/src.macosx-10.7-x86_64-3.6/fortranobject.h:13: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/arrayobject.h:4: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarrayobject.h:18: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarraytypes.h:1816: /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/npy_1_7_deprecated_api.h:15:2: warning: "Using deprecated NumPy API, disable it by "          "#defining NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION" [-W#warnings] #warning "Using deprecated NumPy API, disable it by " \  ^ /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpqavw1pmi/src.macosx-10.7-x86_64-3.6/fortranobject.c:138:18: warning: comparison of integers of different signs: 'Py_ssize_t' (aka 'long') and 'unsigned long' [-Wsign-compare]         if (size < sizeof(notalloc)) {             ~~~~ ^ ~~~~~~~~~~~~~~~~ 2 warnings generated. 

from demo import sum_of_square 

sum_of_square([1,2,3,4]) 

30.0 

1.4. 在python解释器中调用编译工具

如果有需要在python环境中编译Fortran代码,那需要使用numpy中的f2py子模块

编译Fortran代码需要使用f2py.compile(source, modulename='untitled', extra_args='', verbose=1, source_fn=None,extension=".f")方法,

from numpy import f2py 

with open("demo.f95","rb") as f:     source = f.read() 

f2py.compile(source, modulename='demo1',extension='.f95') 

running build running config_cc unifing config_cc, config, build_clib, build_ext, build commands --compiler options running config_fc unifing config_fc, config, build_clib, build_ext, build commands --fcompiler options running build_src build_src building extension "demo1" sources f2py options: [] f2py:> /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 Reading fortran codes...     Reading file '/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpwef1g0pz.f95' (format:free) Post-processing...     Block: demo1             Block: sum_of_square Post-processing (stage 2)... Building modules...     Building module "demo1"...         Constructing wrapper function "sum_of_square"...           y = sum_of_square(x,[n])     Wrote C/API module "demo1" to file "/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c"   adding '/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c' to sources.   adding '/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6' to include_dirs. copying /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/f2py/src/fortranobject.c -> /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 copying /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/f2py/src/fortranobject.h -> /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 build_src: building npy-pkg config files running build_ext customize UnixCCompiler customize UnixCCompiler using build_ext get_default_fcompiler: matching types: '['gnu95', 'nag', 'absoft', 'ibm', 'intel', 'gnu', 'g95', 'pg']' customize Gnu95FCompiler Found executable /usr/local/bin/gfortran customize Gnu95FCompiler customize Gnu95FCompiler using build_ext building 'demo1' extension compiling C sources C compiler: gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/huangsizhe/anaconda3/include -arch x86_64 -I/Users/huangsizhe/anaconda3/include -arch x86_64  creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62 creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 compile options: '-I/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 -I/Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include -I/Users/huangsizhe/anaconda3/include/python3.6m -c' gcc: /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c:16: In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.h:13: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/arrayobject.h:4: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarrayobject.h:18: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarraytypes.h:1816: /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/npy_1_7_deprecated_api.h:15:2: warning: "Using deprecated NumPy API, disable it by "          "#defining NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION" [-W#warnings] #warning "Using deprecated NumPy API, disable it by " \  ^ /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c:109:12: warning: unused function 'f2py_size' [-Wunused-function] static int f2py_size(PyArrayObject* var, ...)            ^ 2 warnings generated. gcc: /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c:2: In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.h:13: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/arrayobject.h:4: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarrayobject.h:18: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarraytypes.h:1816: /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/npy_1_7_deprecated_api.h:15:2: warning: "Using deprecated NumPy API, disable it by "          "#defining NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION" [-W#warnings] #warning "Using deprecated NumPy API, disable it by " \  ^ /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c:138:18: warning: comparison of integers of different signs: 'Py_ssize_t' (aka 'long') and 'unsigned long' [-Wsign-compare]         if (size < sizeof(notalloc)) {             ~~~~ ^ ~~~~~~~~~~~~~~~~ 2 warnings generated. compiling Fortran sources Fortran f77 compiler: /usr/local/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -m64 -fPIC -O3 -funroll-loops Fortran f90 compiler: /usr/local/bin/gfortran -Wall -g -fno-second-underscore -m64 -fPIC -O3 -funroll-loops Fortran fix compiler: /usr/local/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -Wall -g -fno-second-underscore -m64 -fPIC -O3 -funroll-loops compile options: '-I/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 -I/Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include -I/Users/huangsizhe/anaconda3/include/python3.6m -c' gfortran:f90: /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpwef1g0pz.f95 /usr/local/bin/gfortran -Wall -g -m64 -Wall -g -undefined dynamic_lookup -bundle /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.o /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.o /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpwef1g0pz.o -L/usr/local/Cellar/gcc/8.1.0/lib/gcc/8/gcc/x86_64-apple-darwin17.5.0/8.1.0 -L/usr/local/Cellar/gcc/8.1.0/lib/gcc/8/gcc/x86_64-apple-darwin17.5.0/8.1.0/../../.. -L/usr/local/Cellar/gcc/8.1.0/lib/gcc/8/gcc/x86_64-apple-darwin17.5.0/8.1.0/../../.. -lgfortran -o ./demo1.cpython-36m-darwin.so Removing build directory /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t running build running config_cc unifing config_cc, config, build_clib, build_ext, build commands --compiler options running config_fc unifing config_fc, config, build_clib, build_ext, build commands --fcompiler options running build_src build_src building extension "demo1" sources f2py options: [] f2py:> /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 Reading fortran codes...     Reading file '/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpwef1g0pz.f95' (format:free) Post-processing...     Block: demo1             Block: sum_of_square Post-processing (stage 2)... Building modules...     Building module "demo1"...         Constructing wrapper function "sum_of_square"...           y = sum_of_square(x,[n])     Wrote C/API module "demo1" to file "/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c"   adding '/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c' to sources.   adding '/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6' to include_dirs. copying /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/f2py/src/fortranobject.c -> /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 copying /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/f2py/src/fortranobject.h -> /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 build_src: building npy-pkg config files running build_ext customize UnixCCompiler customize UnixCCompiler using build_ext get_default_fcompiler: matching types: '['gnu95', 'nag', 'absoft', 'ibm', 'intel', 'gnu', 'g95', 'pg']' customize Gnu95FCompiler Found executable /usr/local/bin/gfortran customize Gnu95FCompiler customize Gnu95FCompiler using build_ext building 'demo1' extension compiling C sources C compiler: gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/huangsizhe/anaconda3/include -arch x86_64 -I/Users/huangsizhe/anaconda3/include -arch x86_64  creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62 creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t creating /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 compile options: '-I/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 -I/Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include -I/Users/huangsizhe/anaconda3/include/python3.6m -c' gcc: /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c:16: In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.h:13: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/arrayobject.h:4: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarrayobject.h:18: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarraytypes.h:1816: /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/npy_1_7_deprecated_api.h:15:2: warning: "Using deprecated NumPy API, disable it by "          "#defining NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION" [-W#warnings] #warning "Using deprecated NumPy API, disable it by " \  ^ /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.c:109:12: warning: unused function 'f2py_size' [-Wunused-function] static int f2py_size(PyArrayObject* var, ...)            ^ 2 warnings generated. gcc: /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c:2: In file included from /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.h:13: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/arrayobject.h:4: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarrayobject.h:18: In file included from /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/ndarraytypes.h:1816: /Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include/numpy/npy_1_7_deprecated_api.h:15:2: warning: "Using deprecated NumPy API, disable it by "          "#defining NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION" [-W#warnings] #warning "Using deprecated NumPy API, disable it by " \  ^ /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.c:138:18: warning: comparison of integers of different signs: 'Py_ssize_t' (aka 'long') and 'unsigned long' [-Wsign-compare]         if (size < sizeof(notalloc)) {             ~~~~ ^ ~~~~~~~~~~~~~~~~ 2 warnings generated. compiling Fortran sources Fortran f77 compiler: /usr/local/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -m64 -fPIC -O3 -funroll-loops Fortran f90 compiler: /usr/local/bin/gfortran -Wall -g -fno-second-underscore -m64 -fPIC -O3 -funroll-loops Fortran fix compiler: /usr/local/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -Wall -g -fno-second-underscore -m64 -fPIC -O3 -funroll-loops compile options: '-I/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6 -I/Users/huangsizhe/anaconda3/lib/python3.6/site-packages/numpy/core/include -I/Users/huangsizhe/anaconda3/include/python3.6m -c' gfortran:f90: /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpwef1g0pz.f95 /usr/local/bin/gfortran -Wall -g -m64 -Wall -g -undefined dynamic_lookup -bundle /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/demo1module.o /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/src.macosx-10.7-x86_64-3.6/fortranobject.o /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t/var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpwef1g0pz.o -L/usr/local/Cellar/gcc/8.1.0/lib/gcc/8/gcc/x86_64-apple-darwin17.5.0/8.1.0 -L/usr/local/Cellar/gcc/8.1.0/lib/gcc/8/gcc/x86_64-apple-darwin17.5.0/8.1.0/../../.. -L/usr/local/Cellar/gcc/8.1.0/lib/gcc/8/gcc/x86_64-apple-darwin17.5.0/8.1.0/../../.. -lgfortran -o ./demo1.cpython-36m-darwin.so Removing build directory /var/folders/62/pwdyzlx51_j_3_0lr8zxzbx00000gn/T/tmpx4bqux1t      0 

!f2py -c -m demo demo.f95 --quiet 0

sum_of_square([1,2,3,4]) 

30.0