Python Tutorial: Methods and packages

Key Takeaways

two concepts in Python that are important to understand our methods and packages in Python everything is an object and many objects have methods which are special functions that are attached to the object you can access these by adding a period than the method onto an object for example I can make a string object lower case by calling the lower method on that string this returns a lowercase version of the string like lower many methods don't take any arguments or perform some operation on the object they are attached to while others take one or more arguments methods can be very useful for transforming data for example the format method replaces any curly braces in a string with whatever arguments were passed into the method this makes it very easy to print friendly readable messages about the results of an analysis throughout the course you'll learn how to use a number of methods for different data structures in Python the other big difference is packages in MATLAB any functions that get added to your path are available for you to use immediately but in Python only the most essential functions are accessible in a standard session the Python standard library is distributed with every Python installation and includes many useful general-purpose packages data scientists rely heavily on third-party packages like numpy matplotlib and pandas for data analysis and visualization regardless of whether they are part of the Python standard library or a third party package you have to explicitly import them before you can use them for example the Python math package has functions that implement common mathematical functions like sine cosine and tangent and maintain math constants like pi to have access to these functions you can import them with import math once imported you can access the functions a package contains with a period for example math dot log if there is just a specific part of a package that you want to import say the function log from the math package you can use from to import just thing you want sometimes you want to use a package repeatedly but the name is long and you don't want to type it over and over again for these times Python also supports assigning the package to an alias name using as for example here I've used the syntax import package as alias to import the date-time package from the Python standard library and assign it to the variable DT this shorthand is common for the date-time package and many popular packages have common aliases as well let's get some practice manipulating strings with methods and imp