  readPTU is a python package designed to analyze time-correlated single-photon
counting data. The use of the library promotes the storage of the complete time
arrival information of the photons and full flexibility in post-processing data
for analysis. The library supports the computation of time resolved signal with
external triggers and second order autocorrelation function analysis can be
performed using multiple algorithms that provide the user with different
trade-offs with regards to speed and accuracy. Additionally, a thresholding
algorithm to perform time post-selection is also available. The library has
been designed with performance and extensibility in mind to allow future users
to implement support for additional file extensions and algorithms without
having to deal with low level details. We demonstrate the performance of
readPTU by analyzing the second-order autocorrelation function of the resonance
fluorescence from a single quantum dot in a two-dimensional semiconductor.
