How to find the phase difference between many signals by using python?

[etshoo]

I'm a new user to python. For part of my project, I have 10 signals which more or less are in the form of "sine wave" with the same frequency and amplitude.

I plot each one of them separately and it looks good.

But, when I wanted to average them, I found some strange effect on each other and I supposed that there is a Phase difference between them.

Can anyone help me to determine the phase difference between them? any suggestions?

Thanks

[Henrik_Volkers]

A sine approximation is a linear LSRME fit of a*sin(wt)+b*cos(wt)  and give you amplitude and phase.

Don't know, but I wouldn't wonder if there are already python implementations ...