Python continues to creep up the TIOBE Index, which attempts to rank the world’s programming languages by popularity. It was in fifth place a year ago; now it’s in fourth, potentially threatening C++ for third place. What’s behind this slow-and-steady rise? According to the research note that accompanies each monthly update of TIOBE’s rankings, it’s a combination of schools teaching Python and companies embracing it. “In 2005 there was a study what programming language was taught most at U.S. universities and Java appeared to be a clear number one with 60 percent of all introductory programming courses,” the note added. “Similar research was conducted almost 10 years later in 2014 and the outcome was different. This time Python was a clear winner with more than 70 percent ‘market share.’” First released in 1991, Python is an interpreted high-level programming language, with a huge standard library and a number of popular development environments. It is designed to be easily readable, making it popular among many students who are just learning to code. In recent years, it has also become a favorite of data scientists and analysts, an increasing number of whom use it in place of the R programming language. TIOBE thinks it’s likely that Python “will enter the top 3 [on its list] and even might become the new number 1 in the long run.” That may take some time, however, as Java (in the top slot) and C (in second) enjoy massive user bases, and show no signs of flagging anytime soon. In order to create its rankings, TIOBE leverages data from a number of sources, including Google, Wikipedia, YouTube, and Amazon. Earlier this year, a change to Google’s search algorithms “tweaked” the Index a bit, producing some odd changes in the rankings, but the organization compensated for those spikes with what it calls a “smoothing function.” Whereas there’s usually quite a bit of movement among languages further down the Index, which don’t need that much added adoption in order to jump a few ranks, the languages at the very top rarely shift—which makes Python’s recent movement all the more notable.