Install only available packages using "conda install --yes --file requirements.txt" without error

While installing packages in requirements.txt using conda through the following command

conda install --yes --file requirements.txt

If a package in requirements.txt is not available then it throws a "No package error" such as the one shown below:

Using Anaconda Cloud api site

Fetching package metadata: ....

Error: No packages found in current linux-64 channels matching: nimfa ==1.2.3

You can search for this package on with

>     anaconda search -t conda nimfa ==1.2.3

Instead of throwing an error, is it possible to change this behavior such that it installs all the available packages in requirements.txt and throws a warning for those that are not available?

I would like this because, the package nimfa which the error says is not available, can be pip installed. So if i can change the behavior of conda install --yes --file requirements.txt to just throw a warning for unavailable packages, i can follow it up with the command pip install -r requirments.txt in .travis.yml so TravisCI attempts to install it from either place where it is available.

I ended up just iterating over the lines of the file

$ while read requirement; do conda install --yes $requirement; done < requirements.txt

Edit : If you would like to install a package using pip if it is not available through conda, give this a go:

$ while read requirement; do conda install --yes $requirement || pip install $requirement; done < requirements.txt

Edit : If you are using Windows (credit goes to @Clay):

$ FOR /F "delims=~" %f in (requirements.txt) DO conda install --yes "%f" || pip install "%f"