Python Note

Python Note

• 获取当前工作目录
  workpath = os.path.dirname(os.path.realpath(__file__))

• 获取PATH
  path = os.environ.get('PATH', '')

• 展开当前用户目录
  COCOS2D_PREFIX = os.path.expanduser('~/.cocos2d')

• check python版本

def _check_python_version():
    major_ver = sys.version_info[0]
    if major_ver > 2:
        print ("The python version is %d.%d. But python 2.x is required. (Version 2.7 is well tested)\n"
               "Download it here: https://www.python.org/" % (major_ver, sys.version_info[1]))
        return False

    return True

• 解析json

def loadJson(file_path):
    with open(file_path) as data_file:
        data = json.load(data_file)
        return data****

• 下载文件

def download_file(filename, url):
    print("==> Ready to download '%s' from '%s'" % (filename, url))
    import urllib2
    try:
        u = urllib2.urlopen(url)
    except urllib2.HTTPError as e:
        if e.code == 404:
            print("==> Error: Could not find the file from url: '%s'" % (url))
        print("==> Http request failed, error code: " + str(e.code) + ", reason: " + e.read())
        sys.exit(1)

    f = open(filename, 'wb')
    meta = u.info()
    content_len = meta.getheaders("Content-Length")
    file_size = 0
    if content_len and len(content_len) > 0:
        file_size = int(content_len[0])
    else:
        # github server may not reponse a header information which contains `Content-Length`,
        # therefore, the size needs to be written hardcode here. While server doesn't return
        # `Content-Length`, use it instead

        # print("==> WARNING: Couldn't grab the file size from remote, use 'zip_file_size' section in '%s'" % self._config_path)
        # file_size = self._zip_file_size
        print "NO 'Content-Length'"

    print("==> Start to download, please wait ...")

    file_size_dl = 0
    block_sz = 8192
    block_size_per_second = 0
    old_time=time()

    while True:
        buffer = u.read(block_sz)
        if not buffer:
            break

        file_size_dl += len(buffer)
        block_size_per_second += len(buffer)
        f.write(buffer)
        new_time = time()
        if (new_time - old_time) > 1:
            speed = block_size_per_second / (new_time - old_time) / 1000.0
            status = ""
            if file_size != 0:
                percent = file_size_dl * 100. / file_size
                status = r"Downloaded: %6dK / Total: %dK, Percent: %3.2f%%, Speed: %6.2f KB/S " % (file_size_dl / 1000, file_size / 1000, percent, speed)
            else:
                status = r"Downloaded: %6dK, Speed: %6.2f KB/S " % (file_size_dl / 1000, speed)

            status = status + chr(8)*(len(status) + 1)
            print(status),
            sys.stdout.flush()
            block_size_per_second = 0
            old_time = new_time

    print("==> Downloading finished!")
    f.close()