Move from Excel to Python with Pandas Transcripts
Chapter: Data wrangling with Pandas
Lecture: String and math manipulations
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now that we've done some data manipulation with daytime's let's take a look at strings or
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objects as they're shown. So remember we have our DFM foe and we've got company
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We've got invoice. We've got the skew in the product which are coming through
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his objects. So let's say we wanted to turn the company into an upper case
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Once again, we get the attributes air because pandas doesn't know what we're trying
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to do. There is no attributes for pandas Siri's to convert it to upper. So we need to tell it that we're trying to do a string manipulation and now
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it works so similar to what we did with dot d. T. Now we use dot str and there's a bunch of string manipulations that you
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will likely encounter as you start to wrangle and manipulate your data. So this you can lower case your values into title case s o.
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Many of the string functions that you would expect to use just in General Python are
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available in pandas. Another one that you might want to use is length and similar
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to what we did earlier. If you want to actually make sure this gets incorporate any transformation To make it incorporate back into your data frame.
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You need to make sure you re assign it, so call it upper company. And now we have a new columns.
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Has upper company that has the company name all uppercase. Now we've already talked a little bit about how to do some basic math,
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and I want to just tie this back to the different data types. So what? What pandas knows is if you have a data type that in this
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case is an end or afloat, so it's numeric data type. Then you could do mathematical operations so you can think
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about the mathematical formulas plus minus multiplication as access er's similar to what we did for the strings and the daytime data types.
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So, for instance, if we have the extended amount and we wanted to multiply it by 0.9, so essentially give a 10% discount,
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you just use the standard math functions and pandas knows because it is a numeric value It understands what this operator is,
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so you don't need to use an excess. Er Pan is smart enough to do that for you. There is another way to do math in pandas, and I want to highlight it,
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so you're aware of it. So instead of using the asterisk like you would just to do a normal math multiplication in Python,
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there are different operators on this one. There is when a dot mole there's a division and add,
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and for the most part, we're not going to talk about those in the in
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this course, it's generally I would recommend using mathematical operations As you get started.
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These types of functions will be useful form or advanced chaining of pandas operations, so I want you aware of it.
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But I'm not going to spend a lot of time in the course talking about how to use them. So to close this out,
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I want to dio a little more complex mathematical operation. So let's say we want to create a new price and that new prices 5% higher
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than the old price. And so then we've created a new price column that is 5% higher, and then we want to see what the new extended amount is,
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so we have to multiply that times the new price and the new quant and the old quantity. If we do that and see this new price is going to be
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out here at the end 17. 85. So the old price was 17. We've added that 5% to it, and then this is the new extended amount.
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And if you want to see what the actual total amount is, weaken dio simple formula on that as well.
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So this tells us that the original extended amount was 510,000, and now we are at 535,000,