1. Strings and the slice operator

2. The slice operator
This is the “substring” method which most languages have
Given a string, you can slice pieces of the string
the syntax of the operator uses the square brackets
s[5:7] means the part of the string s which starts at position 5 and includes everything up to but not including position 7, in other words, the characters at position 5 and at position 6
Omitting an argument before the colon means to start at the beginning of the string s[:3] means s[0], s[1] and s[2]
Omitting an argument after the colon means to include the rest of the string s[4:] means s[4], s[5]… up to and including the end of the string

3. slice returns a new string
Suppose s were “abcdef” and you wrote an expression like s[1:4]
Its value is “bcd”, a new string (the original string is not changed at all)
If the expression were on a line by itself, it does nothing!
You need to use the expression IN some statement, like an assignment statement, an if statement, a while statement, a print statement
print(s[1:4]) makes sense
t = s[1:4] makes a copy of the 3 characters as a string and puts it into t
s = s[1:4] this does the same as the statement above, but the previous value of s is also discarded
if s[1:4] == “bcd”: would result in True

4. Be careful of your range
str[i:i+1] is the same as saying str[i]
It is possible to go out of range with slice – don’t go past the end of the string!
You can leave off both the starting and ending points, as in s[:]. This produces a copy of the whole string.