collections之Counter使用

文章目錄

在看Django源码时，知道了Counter，

# Check for duplicate app names.counts = Counter(    app_config.name for app_config in self.app_configs.values())duplicates = [    name for name, count in counts.most_common() if count > 1]if duplicates:    raise ImproperlyConfigured(        "Application names aren't unique, "        "duplicates: %s" % ", ".join(duplicates))
counts = Counter(
    app_config.name for app_config in self.app_configs.values())
duplicates = [
    name for name, count in counts.most_common() if count > 1]
if duplicates:
    raise ImproperlyConfigured(
        "Application names aren't unique, "
        "duplicates: %s" % ", ".join(duplicates))

感觉很不错，比用dict统计方便多了，以后需要计数时，就用Counter。看来collections库是个宝库，要好好看看。