The best answers to the question “Pythonic way to create a long multi-line string” in the category Dev.
+ operator (I know, maybe it’s not the most efficient way to do it, but I’m not really concerned about performance in this stage, just code readability). Example:
var long_string = 'some text not important. just garbage to' + 'illustrate my example';
I tried doing something similar in Python, but it didn’t work, so I used
\ to split the long string. However, I’m not sure if this is the only/best/pythonicest way of doing it. It looks awkward.
query = 'SELECT action.descr as "action", '\ 'role.id as role_id,'\ 'role.descr as role'\ 'FROM '\ 'public.role_action_def,'\ 'public.role,'\ 'public.record_def, '\ 'public.action'\ 'WHERE role.id = role_action_def.role_id AND'\ 'record_def.id = role_action_def.def_id AND'\ 'action.id = role_action_def.action_id AND'\ 'role_action_def.account_id = ' + account_id + ' AND'\ 'record_def.account_id=' + account_id + ' AND'\ 'def_id=' + def_id
If you don’t want a multiline string, but just have a long single line string, you can use parentheses. Just make sure you don’t include commas between the string segments (then it will be a tuple).
query = ('SELECT action.descr as "action", ' 'role.id as role_id,' 'role.descr as role' ' FROM ' 'public.role_action_def,' 'public.role,' 'public.record_def, ' 'public.action' ' WHERE role.id = role_action_def.role_id AND' ' record_def.id = role_action_def.def_id AND' ' action.id = role_action_def.action_id AND' ' role_action_def.account_id = '+account_id+' AND' ' record_def.account_id='+account_id+' AND' ' def_id='+def_id)
In a SQL statement like what you’re constructing, multiline strings would also be fine. But if the extra white space a multiline string would contain would be a problem, then this would be a good way to achieve what you want.
As noted in the comments, concatenating SQL queries in this way is a SQL injection waiting to happen, so use your database’s parameterized queries feature to prevent this. However, I’m leaving the answer as-is otherwise as it directly answers the question asked.
Are you talking about multi-line strings? Easy, use triple quotes to start and end them.
s = """ this is a very long string if I had the energy to type more and more ..."""
You can use single quotes too (3 of them of course at start and end) and treat the resulting string
s just like any other string.
NOTE: Just as with any string, anything between the starting and ending quotes becomes part of the string, so this example has a leading blank (as pointed out by @root45). This string will also contain both blanks and newlines.
' this is a very\n long string if I had the\n energy to type more and more ...'
Finally, one can also construct long lines in Python like this:
s = ("this is a very" "long string too" "for sure ..." )
which will not include any extra blanks or newlines (this is a deliberate example showing what the effect of skipping blanks will result in):
'this is a verylong string toofor sure ...'
No commas required, simply place the strings to be joined together into a pair of parenthesis and be sure to account for any needed blanks and newlines.
I found myself happy with this one:
string = """This is a very long string, containing commas, that I split up for readability""".replace('\n',' ')
Breaking lines by
\ works for me. Here is an example:
longStr = "This is a very long string " \ "that I wrote to help somebody " \ "who had a question about " \ "writing long strings in Python"