import matplotlib._png as _png ImportError: libpng16.so.16: cannot open shared object

[haznav]

The error only occurs during usage in virtualenv. import matplotlib.pyplot occurs the error.I am using python 2.7.6 ubuntu 14.04.Urgent help needed please.

[tacaswell]

Try re-installing from source. That sort of exception tends to pop up when the underlying system libpng get updated (via apt-get) but mpl does not get rebuilt.

There is not much else that we can do without a lot more information (full backtrace, how you installed mpl, mpl version, ...)

I am going to close this as I do not think there is a bug in mpl. I suggest moving to our gitter (https://gitter.im/matplotlib/matplotlib), the mailing list (matplotlib-users@python.org), or ask a question on stackoverflow for further support.