Solved using
https://github.com/cocodataset/cocoapi

Cloning https://github.com/waleedka/coco (which is @waleedka's fork of the coco API), then running

python PythonAPI/setup.py build_ext install

installed pycocotools to site-packages and resolved the import error.

The package pycocotools requires cython and a C compiler to install correctly. You can also install pycocotools as follows:

• On Linux, run pip install git+https://github.com/waleedka/cocoapi.git#egg=pycocotools&subdirectory=PythonAPI

• On Windows, run pip install git+https://github.com/philferriere/cocoapi.git#egg=pycocotools^&subdirectory=PythonAPI

git clone https://github.com/pdollar/coco.git

cd coco/PythonAPI
make
sudo make install
sudo python setup.py install

before doing above steps install cython

Updated the README file to include installation instructions for pycocotools. Thanks @philferriere

thanks!

On sudo make install I've got error:

python setup.py build_ext install
Traceback (most recent call last):
  File "setup.py", line 2, in <module>
    from Cython.Build import cythonize
ImportError: No module named Cython.Build
Makefile:7: recipe for target 'install' failed
make: *** [install] Error 

I am using python 3.6 and I have both cython and h5py, any ideas why this is happening??

$ conda list cython & conda list h5py
[1] 18446
# packages in environment at /home/yerong/local/Anaconda3:
#
# Name                    Version                   Build  Channel
h5py                      2.7.1            py36h3585f63_0  
# packages in environment at /home/yerong/local/Anaconda3:
#
# Name                    Version                   Build  Channel
cython                    0.27.3           py36h1860423_0  

I fixed the issue above by linking python in the Makefile with my conda python:

# Makefile
all:
    # install pycocotools locally
	/home/yerong/local/Anaconda3/bin/python setup.py build_ext --inplace
	rm -rf build

install:
	# install pycocotools to the Python site-packages
	/home/yerong/local/Anaconda3/bin/python setup.py build_ext install
	rm -rf build

I fixed this way:

pip install -U scikit-image
pip install -U cython
pip install git+https://github.com/philferriere/cocoapi.git#egg=pycocotools^&subdirectory=PythonAPI

@utahman Same, but with the command
pip install "git+https://github.com/philferriere/cocoapi.git#egg=pycocotools&subdirectory=PythonAPI"

Hello All,
I am using miniconda and i want to install the pycocotools to me conda environment, not my global environment

When i try to run conda_env/bin/pip install git+https://github.com/waleedka/cocoapi.git#egg=pycocotools&subdirectory=PythonAPI
It prompts me for username and I don't think it is asking for my username.

Does anyone know how to get around this issue?

I am avoiding make install because I am not familiar with make and I don't want to accidentally install things outside of my conda environment.
However, I am opened to suggestions if anyone can tell me how to install to conda environment using make.

--- Update ---
I tried the suggestion from @YerongLi and modified my make file to:
all:
# install pycocotools locally
/home/jkuo/miniconda3/envs/test/bin/python setup.py build_ext --inplace
rm -rf build

install:
# install pycocotools to the Python site-packages
/home/jkuo/miniconda3/envs/test/bin/python setup.py build_ext install
rm -rf build

and then i run the following commands:
make install
python setup.py install

Then I see pycocotools in my site-package:

However, I still get the ModuleNotFoundError: No module named 'pycocotools'

---Fixed---
Follow the solution of this post

run 'conda install notebook' in the env and jupyter notebook again

Thanks,
JC

The solution suggested by @g-mel works like a charm in UbuntuGnome 16.04, Python 3.6 and it directly installs it to site-packages. Thus, no import errors are faced.

The easiest way I found and it has worked for me on Mac, Ubuntu and Windows:

pip3 install git+https://github.com/waleedka/coco.git#subdirectory=PythonAPI

The full installation steps that I use with conda on Python 3.6 (tested this on Ubuntu 18.04 only):

conda install cudatoolkit cudnn tensorflow-gpu keras cython opencv
pip install imgaug
pip install git+https://github.com/waleedka/coco.git#subdirectory=PythonAPI

Thanks @philferriere. The pip install hosted on github repo worked well!