Introduction and lists
Data Types in Python
Jason Myers
Instructor
Data types
- Data type system sets the stage for the capabilities of the language
- Understanding data types empowers you as a data scientist
Container sequences
- Hold other types of data
- Used for aggregation, sorting, and more
- Can be mutable (
list,set) or immutable (tuple) - Iterable
Lists
- Hold data in order it was added
- Mutable
- Index
Accessing single items in list
cookies = ['chocolate chip', 'peanut butter', 'sugar']
cookies.append('Tirggel')
print(cookies)
['chocolate chip', 'peanut butter', 'sugar', 'Tirggel']
print(cookies[2])
sugar
Combining lists
- Using operators, you can combine two lists into a new one
cakes = ['strawberry', 'vanilla']
desserts = cookies + cakes
print(desserts)
['chocolate chip', 'peanut butter', 'sugar', 'Tirggel', 'strawberry', 'vanilla']
.extend()method merges a list into another list at the end
cookies.extend(cakes)
Finding elements in a list
.index()method locates the position of a data element in a list
position = cookies.index('sugar')
print(position)
3
Removing elements in a List
.pop()method removes an item from a list and allows you to save it
name = cookies.pop(position)
print(name)
sugar
print(cookies)
['chocolate chip', 'peanut butter', 'Tirggel']
Iterating over lists
- List comprehensions are a common way of iterating over a list to perform some action on them
titlecase_cookies = [cookie.title() for cookie in cookies]
print(titlecase_cookies)
Chocolate Chip
Peanut Butter
Tirggel
Sorting lists
sorted()function sorts data in numerical or alphabetical order and returns a new list
print(cookies)
['chocolate chip', 'peanut butter', 'Tirggel']
sorted_cookies = sorted(cookies)
print(sorted_cookies)
['Tirggel', 'chocolate chip', 'peanut butter']
Let's practice!
Data Types in Python
