python string, best way to concat

[MRAB]

On 2014-08-27 21:31, dennisearlevans at gmail.com wrote:
>
>    Hi,
>
>    Sorry about the simple question but I am very new to Python.
>
>    Anyway, I have a function that will be used to call a stored procedure and I need to format the string with the correct number of parameter markers for the ODBC driver, fairly standard stuff.
>
>    What I have works but looks ugly, is there a better way to build or concatenate a string or is a list or a tuple a better option?
>
> the function looks like this
>
>    def callSp(self, schema, spName) :
>     sqlCode = "{call " + schema + "." + spName + "("
>     par_Markers = ""
>     y = len(self.param)
>     x = 0
>     while x < y :
>       par_Markers = par_Markers.join("?")
>       if (x < y - 1) :
>         par_Markers = par_Markers.join(", ")
>       x += 1
>     self.cmdText = sqlCode + par_Markers + ")}"
>     self.ExecuteCursor()
>
>     return
>
How many parameters are there? len(self.param)

Make that many placeholders and then join them together with commas:

', '.join(['?'] * len(self.param))

> self.param is a list of parameters.  sself.cmdText is the text that will be used to call the stored procedure.
>
> the function would be called like this
>
>    class.AddParameter(some value 1)
>    class.AddParameter(some value 2)
>    callSp("schemaName", "storedProcedureName")
>
>    the self.cmdText will look like this just before the ExecuteCursor call
>
>    "{call schemaName.StoredProcedureName(?, ?)}"
>
>    the code works, but as I said is a bit ugly, is there better methods?
>