[FIXED] Adding an integer number to all elements of a list that are not integer

Issue

Method 1 : Error : ufunc 'add' did not contain a loop with signature matching types dtype('

x = numpy.array(x)
x_5= x + 5

Method 2 : Error : must be str, not int

x_5 = [x+5 for x in x]

Method 3 : Error : invalid literal for int() with base 10: '-0.081428368' I tried to convert the x data first to integer

x_int = list(map(int, x))

x_5 = [x+5 for x in x]

method 4 : Error : 'numpy.float64' object is not iterable

x = numpy.array(x, dtype=float)
x = numpy.array(x)
x_piu_5= x + 5

Method 5 : Error : float object is not iterable

x_piu_5=[]
xfl=[float(i) for i in x]
x_piu_5[:] = [x + 5 for x in xfl]

Hi All

I am trying to add an integer number to my list which contains a lot of numbers like 0.00085695 , etc, and I have used two methods but I have been unsuccessful

Update 1 : Added method 4 , I have obtained the values I wanted, but the problem now is that it say the numpy.float is not iterable

Update 2 : Added method 5, Should I convert the float to string before iteration ?

Solution

The core of your problem is that your list x contains strings representing floating-point numbers. You need to convert those strings to float objects.

More precisely:

• Method 1 can be fixed by using dtype=float, as suggested on the comments:

  x = numpy.array(x, dtype=float)
  x_5 = x + 5
  

• Method 2 can be fixed by converting the items of x to float values before adding 5:

  x_5 = [float(i) + 5 for i in x]
  

• Method 3 can be fixed by using float instead of int, as your values are not integers but rather floating-point values:

  x_float = list(map(float, x))
  x_5 = [i + 5 for i in x_float]
  

  Note that this solution is equivalent to method 2, just a bit slower and more space consuming, as you are creating an additional list.

• Method 4 can be fixed by removing the spurious x = numpy.array(x) line. You will end up with the same code as method 1.

• As for method 5, I suspect that x is not the usual list, but rather it's a float object.

Other than converting values to the correct type, another thing you should try is to use different variable names for different things. In your code snippets, you're using x both for your lists/arrays and for the elements of those lists. While it's not always strictly required, using different variable names would solve a lot of confusion and save you from many headaches!

Answered By - Andrea Corbellini