TypeError: object of type 'float' has no len()

Question

Here's the error: for j in range (len(rotlati)):

TypeError: object of type 'float' has no len()

I have seen many other posts but I haven't found the solution yet. I'm a bit confused. Please comment if you know what's going on here.

The code is:

m = 22
rlati = numpy.zeros(m)
n = 22
rlongi = numpy.zeros(n)

v = numpy.ndarray((2,),float)

for j in range (len(lati)):
LA = lati[j]
    rlati[j] = LA - latiref

    for i in range (len(longi)):
        LO = longi[i]

    rlongi[i] = LO - longiref

    v[0] = rlati[j]
    v[1] = rlongi[i]

    vv = numpy.matrix(v)
    #transpose of vv as vv.T
    vv = vv.T

    #proper rotation
    vn = R*vv

    #define how many decimals
    vn = numpy.around(vn, decimals =2)

    # rotation of the second column (lati) and third line (longi)
        rotlati = float(vn[0])
    rotlongi = float(vn[1])

s = 22
latidef = numpy.zeros(s)
p = 22
longidef = numpy.zeros(p)

for j in range (len(rotlati)):
RLA = rotlati[j]

    latidef[j] = RLA + latiref

for i in range (len(rotlongi)):
        RLO = rotlongi[i]

    longidef[i]= RLO + longiref

    RLADEF = latidef[j]
    RLODEF = longidef[i]

    return RLADEF, RLODEF

Answer 1

The error is exactly what is says it is. rotlati is a float. You cannot take the len() of a float. Looking at your code, it looks as if you might have meant to create lists called rotlati and rotlongi and append to them on each iteration of your range(len(lati)) loop. Instead you're currently just overwriting the same two floating-point variables on every iteration.

Answer 2

The len argument may be a sequence (string, tuple or list) or a mapping (dictionary). https://docs.python.org/2/library/functions.html#len

Before calling the len function, you should verify if the argument is one of this type. You can call the method isinstance() to verify it. Take a look on how to use it. https://docs.python.org/2/library/functions.html#isinstance