Hello, I have a file as follows: 1 2 3 4 5 6 7 8 9 10 I want to calculate the sum of the above numbers. With a command like below I read a whole line and not individual numbers: inn = open("input.txt", "r") inp = readline(inn) How can I separate numbers on a line? Thank you.

If you want to read the file Character by character, you can use c = read(inn, Char). If you want to read the line, but split it into characters afterwards, you could just index the inp in your code (inp[2]), loop over it (for c in inp), or collect it. If you want to get a Vector{Int} (which is pre…

I would probably use sum on eachmatch directly so I don’t have to allocate a vector of strings with split or a vector of ints (eachline is also not the most performant because it allocates a string per line I think, but it depends on what you need whether more effort is worth it) input.txt 1 2 3 4…

Using eachsplit() seems to be more performant in this case: map(eachline("input.txt")) do line sum(x -> parse(Int, x), eachsplit(line)) end

Ah right that one was added in 1.8! Nice

In case the series of values includes multi-digit elements function sumchars(data) tot = 0 lcv=0 for e in data if (e == ' ') tot=tot+lcv lcv=0 else lcv = lcv*10+codepoint(e)-0x30 end end return tot+lcv end …

[image] rafael.guerra: Using eachsplit() seems to be more performant in this case: Only for the parsing part the line of numbers julia> s4 "1 2 3 4 5 6 7 8 9 10 11 12 13" julia> @btime sum(x -> parse(Int, x), eachsplit(s4)) 739.683 ns (3 allocations: 96 bytes) 91 julia> @btime sumchars…

Simple and fast, if no negative integer or integer power such as 2^8 is provided.

[image] rafael.guerra: if no negative integer or integer power such as 2^8 is provided ok for the first point. But why should powers of 2 cause problems?

I meant that the string “2^8”, or “2*10^9”, is a valid input integer that would not be parsed. Edit: my bad, parse(Int, "2^8") errors too :frowning:

How to read a line character by character?

New to Julia

rocco_sprmnt21 November 17, 2024, 3:58pm 6

here a related question

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How to read a line character by character?

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