Lets say we want to do the following:
name = "John" age = 37 print "Hello, my name is "+name+" and I am " +age+ " old"
The output will be:
cannot concatenate 'str' and 'int' objects
What we are trying to do is print both a string and an integer into a single string, which does not work. What we should do is convert the integer into a string:
name = "John" age = 37 print "Hello, my name is "+name+" and I am " +str(age)+ " old"
Hello, my name is John and I am 37 old
However this is actually expensive in terms of processing and time. There is a better and more efficient way, see “String Substitution“