C++ functions matching the interface and behavior of python string methods with std::string

Is there a strong reason why the current API shies away from ever returning a vector of strings as a direct return value, like the actual Python API?

This is particularly useful with C++11 implementations, where auto segs = split(s, delim) is much more concise than having to make a separate and fully-qualified declaration for the std::vector<std::string> segs object before passing it as a mutable reference. In my understanding, modern compilers have no trouble optimizing away this pattern into an equivalent in-place mutation of the return object.

This isn't really a show stopper, but on Windows the tests don't agree with the behavior, so the abspath tests fail. The actual functionality seems sane and intentional, so I dunno if the fix is to change the behavior of the implementation to be consistent across platforms, or probably just change the expectation of the tests on Windows (or skip the abspath tests on Windows entirely).

Anyhow, here's what it is doing: In test.cpp: PYSTRING_CHECK_EQUAL(pystring::os::path::abspath("", "/net"), "/net");

But on windows the implementation uses "" in canonical names rather than "/", because Windows. So it fails because "\net" isn't equal to "/net" The implementation of abspath on Windows runs return normpath_nt(p); to convert the '/' to '' here https://github.com/wrosecrans/pystring/blob/build/pystring.cpp#L1456

Here is a snippet of the output from running the tests:

Test [pystring] [translate] - PASSED D:\a\1\s\test.cpp:516: FAILED: pystring::os::path::abspath("", "/net") == "/net" values were '\net' and '/net' D:\a\1\s\test.cpp:517: FAILED: pystring::os::path::abspath("../jeremys", "/net/soft_scratch/users/stevel") == "/net/soft_scratch/users/jeremys" values were '\net\soft_scratch\users\jeremys' and '/net/soft_scratch/users/jeremys' D:\a\1\s\test.cpp:518: FAILED: pystring::os::path::abspath("../../../../tmp/a", "/net/soft_scratch/users/stevel") == "/tmp/a" values were '\tmp\a' and '/tmp/a' Test [pystring] [abspath] - FAILED Test [pystring_os_path] [splitdrive] - PASSED Test [pystring_os_path] [isabs] - PASSED

In the context of doing CI for a thing that uses PyString, it's convenient to be able to use the tests as a sanity check to make sure I haven't screwed up something completely in my build setup. I am using CMake to build with the MSVC compiler instead of the Makefile that uses G++, but it's not doing anything particularly exciting:

https://github.com/wrosecrans/pystring/blob/build/CMakeLists.txt

My little app crashes with segfault, here's Valgrind diagnosis (after using pystring::split in code):

6,253 bytes in 117 blocks are possibly lost in loss record 13 of 14
  in pystring::(anonymous namespace)::split_whitespace(std::string const&, std::vector<std::string, std::allocator<std::string> >&, int) in pystring/pystring.cpp:109
  1: operator new(unsigned long) in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so
  2: std::string::_Rep::_S_create(unsigned long, unsigned long, std::allocator<char> const&) in /usr/lib/libstdc++.so.6.0.18
  3: char* std::string::_S_construct<char*>(char*, char*, std::allocator<char> const&, std::forward_iterator_tag) in /usr/lib/libstdc++.so.6.0.18
  4: std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&, unsigned long, unsigned long) in /usr/lib/libstdc++.so.6.0.18
  5: std::string::substr(unsigned long, unsigned long) const in /usr/lib/libstdc++.so.6.0.18
  6: pystring::(anonymous namespace)::split_whitespace(std::string const&, std::vector<std::string, std::allocator<std::string> >&, int) in pystring/pystring.cpp:109
  7: pystring::split(std::string const&, std::vector<std::string, std::allocator<std::string> >&, std::string const&, int) in pystring/pystring.cpp:172
  8: ProcessLine(std::string const&, datastorage&) in main.cpp:54
  9: ProcessFile(char const*) in main.cpp:41
  10: main in main.cpp:28

I fixed the bug so that behavior matches python's implementation of find with an empty string as the source string, and added a small suite of unit tests for the find function (which includes cases for the fixed bugs).

I tried to keep the code style consistent with what's there already, but feel free to alter it in any way you see fit :)

Sure, the python string functions are awesome if you need them in C++, but what is one to do if you need them in python? Perhaps boost python would be appropriate? (Please ping the developers before attempting this task, though). ;)

I need to package this for Fedora Linux in preparation of OpenColorIO 2.0 release. The simple Makefile is not very packager friendly. This should work for any Linux distro and can be updated for MacOS and Windows if needed.

This is intended as an alternative to https://github.com/imageworks/pystring/pull/27

It is a fairly complete CMake implementation (which does start to look a little silly vs the 25 lines of Make 😄 ). I needed it for putting the package in Hunter and maybe it is useful here?

Looks like the way the code is structured, there is a top level abspath call which would call a lower level abspath_posix and abspath_nt depending on which os you built the library on.

As far as testing, all the other tests call the $func_nt and $func_posix directly with appropriate test data which works on both windows/linux system (though arguably you may be testing more than you need to test).

For some reason, abspath was the only one testing the top level abspath call. So I just changed to test both nt and posix like the others + appropriate test inputs for the windows version.

This line deadlocks if path has double slash, like in "D:/dir//"

https://github.com/imageworks/pystring/blob/c2de99deb4f0bd13751f8436400b5e8662301769/pystring.cpp#L1364

I think the fix is to slice head2, not head: head2 = pystring::slice(head2,0,-1);

I noticed the libtool arguments don't work on mac os x. I provided a small wscript for using with the waf build system:

https://waf.io

Thought I would push in case you folks would be interested.

I also added a rule to build a pkg-config file for the library.

http://code.google.com/p/pystring/issues/detail?id=2

Reported by [email protected], Jul 19, 2010

What steps will reproduce the problem?

1. strip("")

What is the expected output? What do you see instead? The expected output is empty string. Instead the function crashes.

What version of the product are you using? On what operating system? My version is from pystring_snapshot_012810.zip. Operating system is Windows XP, compiler is Visual Studio 2008.

Comment 1 by project member [email protected], Feb 8, 2011 The Python strip function returns the original string unaltered when the strip characters is empty.

Last release tag in this repository is v1.1.3 (Oct 17, 2012), however there are more recent commits. Which one do you recommended? The 1.1.3 tagged release or cloning the latest commit? Thank you!

Add removeprefix and removesuffix to pystring. Python 3.9 added removeprefix and removesuffix methods to Pythons string class. Add them to pystring to match the interfaces.