py_compile — 编译 Python 源文件

源代码： Lib/py_compile.py

The py_compile module provides a function to generate a byte-code file from a source file, and another function used when the module source file is invoked as a script.

Though not often needed, this function can be useful when installing modules for shared use, especially if some of the users may not have permission to write the byte-code cache files in the directory containing the source code.

exception py_compile. PyCompileError

Exception raised when an error occurs while attempting to compile the file.

py_compile. compile ( file , cfile = None , dfile = None , doraise = False , optimize = -1 , invalidation_mode = PycInvalidationMode.TIMESTAMP , quiet = 0 )

Compile a source file to byte-code and write out the byte-code cache file. The source code is loaded from the file named file . The byte-code is written to cfile , which defaults to the PEP 3147 / PEP 488 path, ending in .pyc . For example, if file is /foo/bar/baz.py cfile 将默认为 /foo/bar/__pycache__/baz.cpython-32.pyc for Python 3.2. If dfile is specified, it is used instead of file as the name of the source file from which source lines are obtained for display in exception tracebacks. If doraise is true, a PyCompileError is raised when an error is encountered while compiling file 。若 doraise is false (the default), an error string is written to sys.stderr , but no exception is raised. This function returns the path to byte-compiled file, i.e. whatever cfile value was used.

The doraise and quiet arguments determine how errors are handled while compiling file. If quiet is 0 or 1, and doraise is false, the default behaviour is enabled: an error string is written to sys.stderr , and the function returns None instead of a path. If doraise is true, a PyCompileError is raised instead. However if quiet is 2, no message is written, and doraise 不起作用。

If the path that cfile becomes (either explicitly specified or computed) is a symlink or non-regular file, FileExistsError will be raised. This is to act as a warning that import will turn those paths into regular files if it is allowed to write byte-compiled files to those paths. This is a side-effect of import using file renaming to place the final byte-compiled file into place to prevent concurrent file writing issues.

optimize controls the optimization level and is passed to the built-in compile() function. The default of -1 selects the optimization level of the current interpreter.

invalidation_mode should be a member of the PycInvalidationMode enum and controls how the generated bytecode cache is invalidated at runtime. The default is PycInvalidationMode.CHECKED_HASH 若 SOURCE_DATE_EPOCH environment variable is set, otherwise the default is PycInvalidationMode.TIMESTAMP .

3.2 版改变： Changed default value of cfile 到 PEP 3147 -compliant. Previous default was file + 'c' ( 'o' if optimization was enabled). Also added the optimize 参数。

3.4 版改变： Changed code to use importlib for the byte-code cache file writing. This means file creation/writing semantics now match what importlib does, e.g. permissions, write-and-move semantics, etc. Also added the caveat that FileExistsError 被引发若 cfile is a symlink or non-regular file.

3.7 版改变： The invalidation_mode parameter was added as specified in PEP 552 。若 SOURCE_DATE_EPOCH 环境变量有设置， invalidation_mode will be forced to PycInvalidationMode.CHECKED_HASH .

3.7.2 版改变： The SOURCE_DATE_EPOCH environment variable no longer overrides the value of the invalidation_mode argument, and determines its default value instead.

3.8 版改变： The quiet 参数被添加。