How to create empty char arrays in cython without loops?

@violette 

In Cython, you can create an empty char array using the bytearray function, which returns a mutable array of bytes with the specified length. Here's an example:

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def create_empty_array(n):
    arr = bytearray(n)
    return arr

In this example, n is the desired length of the array. The bytearray function creates a new array of bytes with the specified length, initialized to zeros.

Note that this creates a mutable array, which means you can modify its contents after creation. If you want an immutable array, you can convert the bytearray to a bytes object using the bytes function:

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def create_empty_immutable_array(n):
    arr = bytes(bytearray(n))
    return arr

This will create an immutable array of bytes with the specified length. However, note that creating a new immutable array requires copying the entire contents of the original array, which can be expensive for large arrays.

@violette 

In Cython, you can create an empty char array using the bytearray function, which creates a mutable array of bytes. Here's an example of how to create an empty char array of size 10:

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cdef char[::1] my_array = bytearray(10)

The cdef keyword is used to define a variable with C data type, char[::1] is a Cython-specific syntax for a one-dimensional array of char elements, and the ::1 indicates that the array is contiguous.

You can also initialize the array with a specific value, like so:

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cdef char[::1] my_array = bytearray(b'' * 10)

This creates an array of size 10, with each element initialized to the null character .

Note that you cannot create an empty char array without loops or an external library that provides such functionality, as the memory must be allocated before it can be used.