- Sequence Operations 0:57
- Slices 4:29
- Creating Slices 1 objective
- Len, Min, and Max 3:04
- Finding len, min, max 3 objectives
- Membership Testing 2:16
- Count and Index 4:38
- Code Samples: Membership Testing, Count, and Index
- Concatenation and Multiplication 3:04
- Sequence Operations Cheat Sheet
- Recap of Sequence Operations 4 questions
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Concatenation and Multiplication
3:04Learn how to combine sequences with concatenation and multiplication
Welcome to the final lesson
of Python sequences.
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In this video, we're going to
be discussing concatenation and
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multiplication of Python sequences.
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Concatenation is when you attach one
object to the end of another, so together,
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they become one larger object.
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For mutable sequence types, like lists,
this concatenation can be done in place,
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the original list can
become a larger list.
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For immutable sequence types,
like tuples and
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strings, concatenation always involves
creating an entirely new object.
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This is not very memory efficient.
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So if you're making repeated
concatenations on an immutable type,
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you might want to consider
a different data structure.
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Concatenation is done by using
what looks like simple addition,
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the plus sign, let's take a look.
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Here I have two lists,
object1 and object2.
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To concatenate, I just add them together.
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What do you think will
happen if print out object1?
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Let's find out.
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As you can see, object1 now contains all
the elements of object1 and object2.
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It's important to note that it
doesn't matter if the sequences you're
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concatenating have any
overlapping elements.
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Concatenation simply attaches the second
object to the end of the first and
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ignores the contents.
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It won't try to merge the objects,
remove duplicates, or
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change the order of a sequence in any way.
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Pause the video here and
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take a moment to play with concatenation
in your attached workspace.
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What happens if you change
the provided list to tuples?
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What if you change them to strings?
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When you're done exploring concatenation,
come back, and
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we'll wrap up with multiplication.
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How did it go, did you learn anything new?
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Now, we'll move on to multiplication.
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This is basically
concatenation multiple times.
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It's also called repetition.
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When you multiply a sequence,
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you concatenate that sequence to
itself the provided number of times.
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The syntax for that is the sequence name,
an asterisk, which means multiply,
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and then the number of times it
should be repetitively concatenated.
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For this example,
we'll use a short string.
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To multiply this string five times,
I'll use the code, str*5.
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Now, let's wrap this in a print statement,
And save it, and run it.
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All right, it printed out python
concatenated together five times,
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great work.
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Check out the teacher's notes to
learn more about immutability and
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concatenation and multiplication.
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See the following text step for
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more examples of both using
different sequence types.
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I'm really proud of the work
you've done in this course.
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Finish up with a code challenge and a quiz
and celebrate your accomplishment, and
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don't forget, keep on coding.
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