Where is this \n coming from in my arrays (Python)?

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I'm trying to create a text string for the following numpy array:

A = array([0, 0, 0, 0, 0.64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0])

I can do this easily with this line of code:

text = f'{A}'

The problem I'm having is that whenever I use this f'{}' to create a string from an array, it outputs the same array, but with a \n after some characters:

text
'[0.   0.   0.   0.64 0.   0.   0.   0.   0.   0.   0.   0.   0.   0.\n 1.   0.   0.   0.  ]'

I'm trying to use this array in the title of a plot, so I don't want the array to be text wrapping onto a new line because it makes it confusing to read/see.

I've tried using rstrip('\n') on text but it doesn't remove the '\n'. Does anyone have any idea what's going on? Why is this \n popping up in the string array?

newline word-wrap arrays python
2 Answers

You don't need to declare array() to accomplish what you are trying to do:

A = [0, 0, 0, 0, 0.64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0]

print(A)
[0, 0, 0, 0, 0.64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0]

print(f'{A}')
[0, 0, 0, 0, 0.64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0] 

A
[0, 0, 0, 0, 0.64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0]

It seems like you are creating a NumPy N-dimensional array there and then converting it to a string, so it is printing the string representation of that array when you call print(). Unless you specifically need a NumPy array, you can do it just like I have above, or if you need to:

    from numpy import array
    A = [0, 0, 0, 0, 0.64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0]
    B = array(A)

    print(B)
    [0.   0.   0.   0.   0.64 0.   0.   0.   0.   0.   0.   0.   0.   0.
     0.   1.   0.   0.   0.  ]

    print(f'{B}')
    [0.   0.   0.   0.   0.64 0.   0.   0.   0.   0.   0.   0.   0.   0.
     0.   1.   0.   0.   0.  ]

     B
     array([0.  , 0.  , 0.  , 0.  , 0.64, 0.  , 0.  , 0.  , 0.  , 0.  , 0.  ,
       0.  , 0.  , 0.  , 0.  , 1.  , 0.  , 0.  , 0.  ])

If you absolutely have to render a NumPy array as a string, then you can do something like this:

  text = f'{A}'
  text = text.replace("\n","")

Or as Ramón Márquez also mentioned, you can simply increase the printoptions line width:

numpy.set_printoptions(linewidth=96)

Documentation on NumPy arrays: https://machinelearningmastery.com/gentle-introduction-n-dimensional-arrays-python-numpy/

Documentation on NumPy print options: https://numpy.org/doc/1.18/reference/generated/numpy.printoptions.html

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