python中的“ ++”是什么意思？

Question

I'm reading a python book. It's explaining for loops and range() function.

But I don't understand what does '+ and +' mean.

for i in range(7):
    print('hello('+str(i)+')')

Answer 1

Actually it should read as:

string_a + string_b + string_c

It is not about "+ xxx +".

It literally concatenate string_a, string_b and string_c together albeit it is not pythonic.

A more pythonic way may be:

print( "hello({my_var})".format(my_var=i) )