converting a tuple consisting of floats and text to one single string

I'm trying to convert a tuple consisting of 2 floats and 3 parts of text to one string so I can use it in file.write() because it is not accepting tuples.

testr = 'you went' ,speed ,'mph and stopped in' ,stop ,'meters'
test = open('testresults.txt' ,'w')
test.write(testr)
test.close()

whenever I try to run the program it gives me this

    test.write(testr)
TypeError: must be str, not tuple