Warning: file_get_contents(/data/phpspider/zhask/data//catemap/0/jpa/2.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
Python 如何将列表应用于string.format()参数?_Python_List_String Formatting - Fatal编程技术网

Python 如何将列表应用于string.format()参数?

Python 如何将列表应用于string.format()参数?,python,list,string-formatting,Python,List,String Formatting,Python2.x 示例CSV输入(我有很多) 期望输出: insert into mytable (ip, bytes, type, timestamp) values ('67.60.60.24', 1384, 'application/octet-stream', '2015-02-18') 到目前为止: sqlTemplate = "insert into mytable (ip, bytes, type, timestamp) values ('{0}', {1}, '{2}', '

Python2.x 示例CSV输入(我有很多)

期望输出:

insert into mytable (ip, bytes, type, timestamp) values ('67.60.60.24', 1384, 'application/octet-stream', '2015-02-18')
到目前为止:

sqlTemplate = "insert into mytable (ip, bytes, type, timestamp) values ('{0}', {1}, '{2}', '{3}')

# lines contains many of the above sample input CSV lines

for line in lines:
  list = line.split(",")
  list = [elem.strip() for elem in list] # whitespace strip each element
  # Make sure len(list) == 4
  if len(list) != 4:
    continue
  sql = sqlTemplate.format(list) # how can i apply the list to the args?
  # todo: insert sql into DB

您可以使用*运算符解压缩列表

就你而言

sql = sqlTemplate.format(*list)
如果您的列表为[“a”、“b”、“c”],则此代码与以下代码相同:

sql = sqlTemplate.format("a", "b", "c")

但是,当然,现在可以使用不同数量的参数调用format函数

不要使用字符串格式来生成SQL。改用SQL参数。哦…是的!非常感谢。
sql = sqlTemplate.format("a", "b", "c")