CODEWITHSUNDEEP
stringcython
paulinho
paulinho

Reputation: 302

Casting int to str in cython?

I have a very simple question on how to cast an int to string in Cython. I wish to concatenate a variable number to a phrase, e.g.

cdef str consPhrase = "attempt"
cdef int number = 7     #variable
cdef str newString = consPhrase + <str>number    #so it should be "attempt7", "attempt8", etc.

However, I keep getting an error claiming

TypeError: Expected str, got int

I've looked on how to cast in Cython, and it claims that it is down with the < > brackets, so why isn't the int being converted into the str?

I've even tried

cdef str makeStr(str l):
    return l


cdef str consPhrase = "attempt"
cdef int number = 7
cdef str newString = consPhrase + makeStr(number)

but it throws the same error on the same line (the cdef str newString = consPhrase + makeStr(number) line). So, what is the most efficient and correct way of doing this simple task? Any help would be appreciated!

Upvotes: 2

Views: 2239

Answers (1)

ngoldbaum
ngoldbaum

Reputation: 5590

The easiest way to do this is just to convert the data to a string, just like you would in any other python code:

cdef str newString = consPhrase + str(number)

Casting like you are trying to do won't work because str is a Python type which maps to bytes in Python2 and unicode in Python3. Since it might be a unicode string, there's no safe way to cast an integer to a string like you're trying to do.

Upvotes: 3

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