fatal error: Python.h: No such file or directory

Question

I am trying to build a shared library using a C extension file but first I have to generate the output file using the command below:

gcc -Wall utilsmodule.c -o Utilc

After executing the command, I get this error message:

> utilsmodule.c:1:20: fatal error: Python.h: No such file or directory
compilation terminated.

I have tried all the suggested solutions over the internet but the problem still exists. I have no problem with Python.h. I managed to locate the file on my machine.

Answer 1

The high voted answers are all correct, but for me, one important prerequisite is missing, and I keep failing.

sudo apt-get update
sudo apt-get install python3-dev

It is important to update before install for some circumtances

Reference: https://www.geeksforgeeks.org/how-to-fix-fatal-error-python-h-no-such-file-or-directory/

Answer 2

Looks like you haven't properly installed the header files and static libraries for python dev. Use your package manager to install them system-wide.

For apt (Ubuntu, Debian...):

sudo apt-get install python-dev   # for python2.x installs
sudo apt-get install python3-dev  # for python3.x installs

For yum (CentOS, RHEL...):

sudo yum install python-devel    # for python2.x installs
sudo yum install python3-devel   # for python3.x installs

For dnf (Fedora...):

sudo dnf install python2-devel  # for python2.x installs
sudo dnf install python3-devel  # for python3.x installs

For zypper (openSUSE...):

sudo zypper in python-devel   # for python2.x installs
sudo zypper in python3-devel  # for python3.x installs

For apk (Alpine...):

# This is a departure from the normal Alpine naming
# scheme, which uses py2- and py3- prefixes
sudo apk add python2-dev  # for python2.x installs
sudo apk add python3-dev  # for python3.x installs

For apt-cyg (Cygwin...):

apt-cyg install python-devel   # for python2.x installs
apt-cyg install python3-devel  # for python3.x installs

Important Note: python3-dev/devel does not automatically cover all minor versions of python3.
E.g If you are using python 3.11 you may need to install python3.11-dev / python3.11-devel.

Answer 3

sudo yum -y install python3.11-devel.x86_64

Answer 4

For Python 3.7 and Ubuntu in particular, I needed

sudo apt install libpython3.7-dev

. I think at some point names were changed from pythonm.n-dev to this.

for Python 3.6, 3.8 through 3.10 (and counting…) similarly:

sudo apt install libpython3.6-dev 

sudo apt install libpython3.8-dev 

sudo apt install libpython3.9-dev

sudo apt install libpython3.10-dev

sudo apt install libpython3.11-dev

sudo apt install libpython3.12-dev

Answer 5

This problem can also arise when you have different Python versions installed and you use a pip that's not the system's one. In that case, the non-system pip won't find the right version of Python headers.

It happened to me when trying to pip install a package for a Python bundled with an application. As it was not system's python, apt install pythonXX-dev didn't work.

In this case, the solution is to find the right python header:

find / -iname 'Python.h'

In the output, you will see system python headers, and hopefully the one you are looking for, for example:

/usr/include/python3.7m/Python.h
/usr/include/python3.6m/Python.h
/home/ubuntu/workspace/blender-git/lib/linux_centos7_x86_64/python/include/python3.7m/Python.h
/home/ubuntu/miniconda3/pkgs/python-3.8.5-h7579374_1/include/python3.8/Python.h
/home/ubuntu/miniconda3/pkgs/python-3.7.0-h6e4f718_3/include/python3.7m/Python.h
/home/ubuntu/miniconda3/include/python3.8/Python.h
/home/ubuntu/miniconda3/envs/sim/include/python3.7m/Python.h
/home/ubuntu/src/blender-deps/Python-3.7.7/Include/Python.h
/opt/lib/python-3.7.7/include/python3.7m/Python.h

Then, you can set a compiler flag that will get used by gcc when called by pip. Mine was /home/ubuntu/workspace/blender-git/lib/linux_centos7_x86_64/python/include/python3.7m/Python.h, so I did:

export CPPFLAGS=-I/home/ubuntu/src/blender-deps/Python-3.7.7/Include
pip install <package>

Answer 6

The problem maybe that you do not have the appropiate Python Library headers installed. If you use Linux Solus, this can be solved by using the command:

sudo eopkg install python3-devel

Answer 7

In case you already have Python installed, and want to link against a specific Python version, you can get the relevant include path from Python.

>>> import sysconfig
>>> sysconfig.get_path('include')
'/usr/include/python3.10' # Example output

You can manually specify the include path/build against a specific python version using a shell script:

#!/bin/sh
python_include=$(python3.10 -c "import sysconfig; print(sysconfig.get_path('include'))")
gcc -Wall utilsmodule.c -o Utilc -I"$python_include"

Answer 8

It is confirmed that if you are running centos 8+. You will need to run the followings:

sudo yum -y install python36 python38 python39
sudo yum -y install python36-devel.x86_64 python38-devel.x86_64 python39-devel.x86_64

pip3.8 install cpython
pip3.9 install cpython
pip3.6 install cpython

Answer 9

I am on Ubuntu. I have installed all packages as was recommended in some answers.

sudo apt-get install python-dev   # for python2.x installs
sudo apt-get install python3-dev  # for python3.x installs

I still had this problem, the line:

#include "Python.h"

And some others, I can edit them manually, it is a bad practice. I know the secret now, it comes from the cython source code. I have the file. It compiles without errors. That is the file. Change PYTHON to python version you have, python/python3. Change FILE to your c-filename. The name of the makefile file should be Makefile. Run the the file with the command:

make all

Makefile for creating our standalone Cython program

    FILE := file.c
    PYTHON := python3
    PYVERSION := $(shell $(PYTHON) -c "import sys;                     
    print(sys.version[:3])")
    PYPREFIX := $(shell $(PYTHON) -c "import sys; print(sys.prefix)")

    INCDIR := $(shell $(PYTHON) -c "from distutils import sysconfig; 
    print(sysconfig.get_python_inc())")
    PLATINCDIR := $(shell $(PYTHON) -c "from distutils import 
    sysconfig; print(sysconfig.get_python_inc(plat_specific=True))")
    LIBDIR1 := $(shell $(PYTHON) -c "from distutils import sysconfig; 
    print(sysconfig.get_config_var('LIBDIR'))")
    LIBDIR2 := $(shell $(PYTHON) -c "from distutils import sysconfig; 
    print(sysconfig.get_config_var('LIBPL'))")
    PYLIB := $(shell $(PYTHON) -c "from distutils import sysconfig; 
    print(sysconfig.get_config_var('LIBRARY')[3:-2])")

    CC := $(shell $(PYTHON) -c "import distutils.sysconfig; 
    print(distutils.sysconfig.get_config_var('CC'))")
    LINKCC := $(shell $(PYTHON) -c "import distutils.sysconfig; 
    print(distutils.sysconfig.get_config_var('LINKCC'))")
    LINKFORSHARED := $(shell $(PYTHON) -c "import distutils.sysconfig; 
    print(distutils.sysconfig.get_config_var('LINKFORSHARED'))")
    LIBS := $(shell $(PYTHON) -c "import distutils.sysconfig; 
    print(distutils.sysconfig.get_config_var('LIBS'))")
    SYSLIBS :=  $(shell $(PYTHON) -c "import distutils.sysconfig; 
    print(distutils.sysconfig.get_config_var('SYSLIBS'))")

    .PHONY: paths all clean test

    paths:
        @echo "PYTHON=$(PYTHON)"
        @echo "PYVERSION=$(PYVERSION)"
        @echo "PYPREFIX=$(PYPREFIX)"
        @echo "INCDIR=$(INCDIR)"
        @echo "PLATINCDIR=$(PLATINCDIR)"
        @echo "LIBDIR1=$(LIBDIR1)"
        @echo "LIBDIR2=$(LIBDIR2)"
        @echo "PYLIB=$(PYLIB)"
        @echo "CC=$(CC)"
        @echo "LINKCC=$(LINKCC)"
        @echo "LINKFORSHARED=$(LINKFORSHARED)"
        @echo "LIBS=$(LIBS)"
        @echo "SYSLIBS=$(SYSLIBS)"

    $(FILE:.c=): $(FILE:.c=.o)
        $(LINKCC) -o $@ $^ -L$(LIBDIR1) -L$(LIBDIR2) -l$(PYLIB)         
    $(LIBS) $(SYSLIBS) $(LINKFORSHARED)

    $(FILE:.c=.o): $(FILE)
        $(CC) -c $^ -I$(INCDIR) -I$(PLATINCDIR)

    all: $(FILE:.c=)

Answer 10

Here is yet another solution, because none of these solutions worked for me. For reference, I was trying to pip install something on an Amazon Linux AMI base Docker image for Python 3.6.

Non-docker solution:

# Install python3-devel like everyone says
yum -y install python36-devel.x86_64

# Find the install directory of `Python.h`
rpm -ql python36-devel.x86_64 | grep -i "Python.h"

# Forcefully add it to your include path
C_INCLUDE_PATH='/usr/include/python3.6m'
export C_INCLUDE_PATH

Docker solution:

# Install python3-devel like everyone says
RUN yum -y install python36-devel.x86_64

# Find the install directory of `Python.h`, for me it was /usr/include/python3.6m
RUN rpm -ql python36-devel.x86_64 | grep -i "Python.h" && fake_command_so_docker_fails_and_shows_us_the_output

# Since the previous command contains a purposeful error, remove it before the next run

# Forcefully add it to your include path
ARG C_INCLUDE_PATH='/usr/include/python3.6m'

NOTE: If you're getting the error when compiling C++, use CPLUS_INCLUDE_PATH.

Alternatively, you may prefer to use another Docker image. For example, I was trying to install asyncpg~=0.24.0 on python:3.9.4-slim, which generated the same error as you saw. However, when I updated the image to python:3, it worked fine.

Answer 11

The situation I encountered is my Python.h in the directory /usr/include/python3.8 and /usr/include/python2.7，just give the path to gcc by like -I /usr/include/python3.8。python's version replace with yours。

Answer 12

If you use cmake to build project, you can use this example.

cmake_minimum_required(VERSION 2.6)
project(demo)
find_package(PythonLibs REQUIRED)
include_directories(${PYTHON_INCLUDE_DIRS})
add_executable(demo main.cpp)
target_link_libraries(demo ${PYTHON_LIBRARIES})

Answer 13

try locate your Python.h:

gemfield@ThinkPad-X1C:~$ locate Python.h
/home/gemfield/anaconda3/include/python3.7m/Python.h
/home/gemfield/anaconda3/pkgs/python-3.7.6-h0371630_2/include/python3.7m/Python.h
/usr/include/python3.8/Python.h

if not found, then install python-dev or python3-dev; else include the correct header path for compiler:

g++ -I/usr/include/python3.8 ...

Answer 14

Make sure that the Python dev files come with your OS.

You should not hard code the library and include paths. Instead, use pkg-config, which will output the correct options for your specific system:

$ pkg-config --cflags --libs python2
-I/usr/include/python2.7 -lpython2.7

You may add it to your gcc line:

gcc -Wall utilsmodule.c -o Utilc $(pkg-config --cflags --libs python2) 

Answer 15

1. You must install the Python development files on your operating system if the Python provided with your operating system does not come with them. The many answers on this question show the myriad ways this can be achieved on different systems.

2. When you have done so, the problem is telling the compiler where they're located and how to compile against them. Python comes with a program called python-config. For compilation, you need the --includes output and for linking a program against the Python library (embedding Python into your program) the --ldflags output. Example:

   gcc -c mypythonprogram.c $(python3-config --includes)
   gcc -o program mypythonprogram.o $(python3-config --ldflags)
   

The python-config program can be named after the Python versions - on Debian, Ubuntu for example these can be named python3-config or python3.6-config.

Answer 16

Solution for Cygwin

You need to install the package python2-devel or python3-devel, depending on the Python version you're using.

You can quickly install it using the 32-bit or 64-bit setup.exe (depending on your installation) from Cygwin.com.

Example (modify setup.exe's filename and Python's major version if you need):

$ setup.exe -q --packages=python3-devel

You can also check my other answer for a few more options to install Cygwin's packages from the command-line.

Answer 17

It's not the same situation, but it also works for me and now I can use SWIG with Python3.5:

I was trying to compile:

gcc -fPIC -c existe.c existe_wrap.c -I /usr/include/python3.5m/

With Python 2.7 works fine, not with my version 3.5:

existe_wrap.c:147:21: fatal error: Python.h: No existe el archivo o el directorio compilation terminated.

After run in my Ubuntu 16.04 installation:

sudo apt-get install python3-dev  # for python3.x installs

Now I can compile without problems Python3.5:

gcc -fPIC -c existe.c existe_wrap.c -I /usr/include/python3.5m/

Answer 18

Sure python-dev or libpython-all-dev are the first thing to (apt )install, but if that doesn't help as was my case, I advice you to install the foreign Function Interface packages by sudo apt-get install libffi-dev and sudo pip install cffi.

This should help out especially if you see the error as/from c/_cffi_backend.c:2:20: fatal error: Python.h: No such file or directory.

Answer 19

Sometimes even after installing python-dev the error persists, Check for the error if it is 'gcc' missing.

First download as stated in https://stackoverflow.com/a/21530768/8687063, then install gcc

For apt (Ubuntu, Debian...):

sudo apt-get install gcc

For yum (CentOS, RHEL...):

sudo yum install gcc

For dnf (Fedora...):

sudo dnf install gcc

For zypper (openSUSE...):

sudo zypper in gcc

For apk (Alpine...):

sudo apk gcc

Answer 20

I also encountered this error when I was installing coolprop in ubuntu.

For ubuntu 16.04 with python 3.6

sudo apt-get install python3.6-dev

If ever this doesn't work try installing/updating gcc lib.

sudo apt-get install gcc

Answer 21

It often appear when you trying to remove python3.5 and install python3.6.

So when using python3 (which python3 -V => python3.6) to install some packages required python3.5 header will appear this error.

Resolve by install python3.6-dev module.

Answer 22

If you're using Python 3.6 on Amazon Linux (based on RHEL, but the RHEL answers given here didn't work):

sudo yum install python36-devel

Answer 23

On Ubuntu, I was running Python 3 and I had to install

sudo apt-get install python3-dev

If you want to use a version of Python that is not linked to python3, install the associated python3.x-dev package. For example:

sudo apt-get install python3.5-dev

Answer 24

For CentOS 7:

sudo yum install python36u-devel

I followed the instructions here for installing python3.6 on several VMs: https://www.digitalocean.com/community/tutorials/how-to-install-python-3-and-set-up-a-local-programming-environment-on-centos-7 and was then able to build mod_wsgi and get it working with a python3.6 virtualenv

Answer 25

This error occurred when I attempted to install ctds on CentOS 7 with Python3.6. I did all the tricks mentioned here including yum install python34-devel. The problem was Python.h was found in /usr/include/python3.4m but not in /usr/include/python3.6m. I tried to use --global-option to point to include dir (pip3.6 install --global-option=build_ext --global-option="--include-dirs=/usr/include/python3.4m" ctds). This resulted in a lpython3.6m not found when linking ctds.

Finally what worked was fixing the development environment for Python3.6 needs to correct with the include and libs.

yum -y install https://dl.iuscommunity.org/pub/ius/stable/CentOS/7/x86_64/python36u-libs-3.6.3-1.ius.centos7.x86_64.rpm

Python.h needs to be in your include path for gcc. Whichever version of python is used, for example if it's 3.6, then it should be in /usr/include/python3.6m/Python.h typically.

Answer 26

on Fedora run this for Python 2:

sudo dnf install python2-devel

and for Python 3:

sudo dnf install python3-devel

Answer 27

If you use a virtualenv with a 3.6 python (edge right now), be sure to install the matching python 3.6 dev sudo apt-get install python3.6-dev, otherwise executing sudo python3-dev will install the python dev 3.3.3-1, which won't solve the issue.

Answer 28

For me, changing it to this worked:

#include <python2.7/Python.h>

I found the file /usr/include/python2.7/Python.h, and since /usr/include is already in the include path, then python2.7/Python.h should be sufficient.

You could also add the include path from command line instead - gcc -I/usr/lib/python2.7 (thanks @erm3nda).

Answer 29

AWS EC2 install running python34:

sudo yum install python34-devel

Answer 30

In my case, what fixed it in Ubuntu was to install the packages libpython-all-dev (or libpython3-all-dev if you use Python 3).