Editing Community Data Science Course (Spring 2015)/Day 1 Tutorial (section)

====compound conditionals: <code>and</code> and <code>or</code>====

You can check multiple expressions together using the '''<code>and</code>''' and '''<code>or</code>''' keywords. If two expressions are joined by an <code>and</code>, they '''both''' have to be <code>True</code> for the overall expression to be <code>True</code>. If two expressions are joined by an <code>or</code>, as long as '''at least one''' is <code>True</code>, the overall expression is <code>True</code>.

Try typing these out and see what you get:

<pre>
1 > 0 and 1 < 2
</pre>

<pre>
1 < 2 and "x" in "abc"
</pre>

<pre>
"a" in "hello" or "e" in "hello"
</pre>

<pre>
1 <= 0 or "a" not in "abc"
</pre>

Guess what will happen when you enter these next two examples, and then type them out and see if you are correct. If you have trouble with the indenting, call over a staff member and practice together. It is important to be comfortable with indenting for tomorrow.

<pre>
temperature = 32
if temperature > 60 and temperature < 75:
    print("It's nice and cozy in here!")
else:
    print("Too extreme for me.")
</pre>

<pre>
hour = 11
if hour < 7 or hour > 23:
    print("Go away!")
    print("I'm sleeping!")
else:
    print("Welcome to the cheese shop!")
    print("Can I interest you in some choice gouda?")
</pre>

You can have as many lines of code as you want in <code>if</code> and <code>else</code> blocks; just make sure to indent them so Python knows they are a part of the block.