E: Unable to locate package python3-pip docker file

The solution for this is noted below

E: Unable to locate package python3-pip docker file

Solution

....

# use this for ubuntu 14.04 or 16.04
RUN apt-get update -y && apt-get install -y software-properties-common && add-apt-repository ppa:deadsnakes/ppa

RUN apt-get update -y && apt-get install -y \
 python3.6 \
 python3-pip \
 curl \
 git

RUN pip3 install --upgrade pip

...

Try other methods by searching on the site. That is if this doesn’t work