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Simple rollback on error with contextlib.ExitStack
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| import os | |
| import shutil | |
| from contextlib import ExitStack | |
| def create_folder(stack: ExitStack, path): | |
| try: | |
| os.mkdir(path) | |
| except FileExistsError: | |
| pass | |
| if not os.path.isdir(path): | |
| raise NotADirectoryError(repr(path)) | |
| stack.callback(lambda: os.rmdir(path)) | |
| def copy_file(stack: ExitStack, src, dst): | |
| shutil.copyfile(src, dst) | |
| stack.callback(lambda: os.unlink(dst)) | |
| def main(): | |
| with ExitStack() as stack: | |
| create_folder(stack, './foobar') | |
| copy_file(stack, './foo.json', './foobar/spam.json') | |
| copy_file(stack, './foo.json', './foobar/spam1.json') | |
| copy_file(stack, './foo.json', './foobar/spam2.json') | |
| copy_file(stack, './foo.json', './foobar/spam3.json') | |
| copy_file(stack, './foo.json', './foobar/spam4') | |
| create_folder(stack,'./foobar/spam4') # Error! | |
| create_folder(stack, './foobar/spam5') | |
| stack.pop_all() # on success, clear exit stack, so the files/folders stay. | |
| if __name__ == '__main__': | |
| main() |
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