Regex for changing :variable to ${variable} in sql query

[MRAB]

On 2018-04-18 08:25, zljubisic at gmail.com wrote:
> Hi,
> 
> I have a sql query in which all variables declared as :variable should be changed to ${variable}.
> 
> for example this sql:
> 
> select *
> from table
> where ":x" = "1" and :y=2
> and   field in (:string)
> and   time between :from and  :to
> 
> 
> should be translated to:
> 
> select *
> from table
> where "${x}" = "1" and ${y} = 2
> and   field in ( ${string} )
> and   time between ${from} and ${to}
> 
> As far as I have come is to find the group as (:(.+?)\b)
> and than replace it as ${$2}
> 
> (it would be nice if before and after the ${variable} it is always one space)
> 
> For opposite change (from ${variable} notation to :variable) I am using:
> 
> sql.replace('${', ':').replace('}', '')
> 
> Can someone please help?
> 
Try this:

new_query = re.sub(r':([a-z][a-z0-9_]*)', r'${\1}', query)

To convert the other way, try this:

new_query = re.sub(r'\$\{([a-z][a-z0-9_]*)\}', r':\1', query)