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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def is_venv():
 """Check whether if this workspace is a virtualenv. """

    dir_path = os.path.dirname(SRC)
    is_venv_flag = True

    if SYS_NAME == "Windows":
        executable_list = ["activate", "pip.exe", "python.exe"]
    elif SYS_NAME in ["Darwin", "Linux"]:
        executable_list = ["activate", "pip", "python"]

    for executable in executable_list:
        path = os.path.join(dir_path, BIN_SCRIPTS, executable)
        if not os.path.exists(path):
            is_venv_flag = False

    return is_venv_flag