【format】 vs 【%】 in Python-蒲公英云

【format】 vs 【%】 in Python

相比【%】，Python中的【format】更显精致，对于【%】来说，它无法同时传递一个变量和元组（Tuple）

比如，对于：

“hi there %s” % name

如果name传递Tuple元组类型参数，那么将抛出如下错误：

TypeError: not all arguments converted during string formatting

为保证其正常执行，你需要这么做，确保参数name为只包含单个元素的元组：

“hi there %s” % (name,) # supply the single argument as a single-item tuple

def format_with_format(obj):
    try:
        return 'hello {name}'.format(name=obj)
    except Exception as e:
        print(e)
        return 'format_with_format error'
def format_with_percent(obj):
    try:
        return 'hello %s' % obj
    except Exception as e:
        print(e)
        return 'format_with_percent error'
def format_with_percent_optimization(obj):
    try:
        return 'hello %s' % (obj,)
    except Exception as e:
        print(e)
        return 'format_with_percent error'
if __name__ == '__main__':
    L = [1, 2, 3]
    T = (1, 2, 3, 4)
    print(format_with_format(L))
    print(format_with_format(T))
    print(format_with_percent(L))
    print(format_with_percent(T))
    print(format_with_percent_optimization(T))