If you have a Linux system, you can use the binary distribution. Uncompress the file and put the binaries somewhere in your PATH.
Another alternative is to install the source distribution.
seq_crumbs depends on python 2.7 or newer and Biopython 1.60 or newer.
An easy way to install Biopython would be to use the packaging system of your Linux distribution or alternatively just run the following command:
$ easy_install biopython
$ pip install biopython
If you don’t have easy_install installed you can grab it from the setuptools site.
Once you have installed the dependencies you can install seq_crumbs:
$ tar -xvzf seq_crumbs-0.1.tar.gz $ cd seq_crumbs-0.1 $ python setup.py install