Python Type Error: 'List' object is not callable
<p>I'm getting this error with this small code content of Python27. Can anyone help me with this? Thanks in advance.</p>

<blockquote>
  <p>Run Time Error Traceback (most recent call last):   File
  "5eb4481881d51d6ece1c375c80f5e509.py", line 57, in 
      print len(arr) TypeError: 'list' object is not callable</p>
</blockquote>

<pre><code>global maximum

def _lis(arr , n ):

    # to allow the access of global variable
    global maximum

    # Base Case
    if n == 1 :
        return 1

    # maxEndingHere is the length of LIS ending with arr[n-1]
    maxEndingHere = 1

    """Recursively get all LIS ending with arr[0], arr[1]..arr[n-2]
       IF arr[n-1] is maller than arr[n-1], and max ending with
       arr[n-1] needs to be updated, then update it"""
    for i in xrange(1, n):
        res = _lis(arr , i)
        if arr[i-1] &lt; arr[n-1] and res+1 &gt; maxEndingHere:
            maxEndingHere = res +1

    # Compare maxEndingHere with overall maximum. And
    # update the overall maximum if needed
    maximum = max(maximum , maxEndingHere)

    return maxEndingHere

def lis(arr):

    # to allow the access of global variable
    global maximum

    # lenght of arr
    n = len(arr)

    # maximum variable holds the result
    maximum = 1

    # The function _lis() stores its result in maximum
    _lis(arr , n)

    return maximum

num_t = input()

len = [None]*num_t

arr = []

for i in range(0,num_t):

    len[i] = input()

    arr.append(map(int, raw_input().split()))

    print len(arr)
    break    
</code></pre>

<p>That is what happens when you define a variable that is also a built-in function name.<br>
Change the variable <code>len</code> to something else.</p>

python list