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Davis Rousseau
6,670 PointsBoolean expression?
Not understanding this question?
Start by executing
s = 'quizzed'
Then write a Boolean expression that check whether
(a) The first character of string s is 'q' (b) The seventh character of s is q (c) The first two character of s is q
This is what I have for a
s[0]
6 Answers
Stephen Harnois
8,656 PointsA Boolean expression is a True or False statement.
(a) If s = 'quizzed' then the we can find the first character by using slicing like you suggest. a = s[0], but to get a Boolean expression you have to ask a true/false question about the value stored in a. You do that by a == 'q'. If you want to check it in one step you can ask if the slice is 'q' like this: s[0] == 'q'
(b) This one is similar to (a) above except we are looking for the seventh character and we have to remember that the index is zero based, so we would use the following Boolean expression: s[6] == 'q'
(c) For this question we are asking if two things are true at the same time. The only way to test if two things are true at the same time is using an and function like this: s[0] == 'q' and s[1] == 'q' . You can also ask this question another way by saying are the first two letters equal to 'qq' and you can do that using the following: s[0:2] == 'qq'
I hope that helps answer the question if you need clarification on any of the steps just let me know. I am glad to help.
Davis Rousseau
6,670 PointsThe first two characters of s are q and a?
s[0] == 'q' and s[1] == 'a'
Kenneth Love
Treehouse Guest TeacherStrings also have an awesome method called startswith() so you could do s.startswith('qa'). Or s[:2] == 'qa'.
Stephen Harnois
8,656 PointsOne of the common principles of programming is called DRY, which stands for "Don't Repeat Yourself". Why would you store the same value in three different variables? You can just use the first variable in multiple locations. If you are instead asking about unpacking a list into multiple variables that can be done by the following: var1, var2, var3 = ['string1', 'string2', 'string3'] Which will result in var1 = 'string1' and var2 = 'string2' and var3 = 'string3' And Yes I do believe that is covered in one of the Python classes taught by Kenneth Love here at Treehouse.
Davis Rousseau
6,670 PointsThanks! Starting to make sense. So does the word is mean == ?
Davis Rousseau
6,670 PointsThanks that's a lot easier.
Davis Rousseau
6,670 PointsHow would I assign 3 variables that has 3 strings that are the same? Any tutorial that shows this?
variables1 = ['string1', 'string2','string3'] variables2 = ['string1', 'string2','string3'] variables3 = ['string1', 'string2','string3']