naif is a pure-python package based on the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm, first proposed by Laskar (1990) and further developed by Valluri & Merritt (1998). Given a time-series, particularly that of an orbital coordinate, it extracts from its power-spectrum as many frequencies and respective amplitudes as required. In comparison to the original NAFF algorithm, it has some improvements, particularly in the performance (computation time). It also offers functions to plot the power-spectrum before extraction of each frequency, which can be useful for debugging particular orbits. The code is fully documented and the documentation page has several tutorials. In the future, the code will be expanded with other tools for frequency analysis.