How does Python split() function works
<pre><code>def loadTest(filename): 
    f=open(filename,'r')
    k=0
    line=f.readline()
    labels=[]
    vectors=[]
    while line and k&lt;4:
        k=k+1
        l=line[:-1].split(r'","')
        s=float(l[0][1:])
        tweet=l[5][:-1]
        print(l)
        line=f.readline()
     f.close()
     return
</code></pre>

<p>What do <code>split(r'","')</code> actually does inside python split method?</p>