Python Jumpstart by Building 10 Apps Transcripts
Chapter: App 1: Hello (you Pythonic) world
Lecture: Core concepts: Variables and calling functions
0:01 The first concept is around this idea of calling functions, print is a function, input is a function
0:07 these are reusable pieces of functionality in our application. Here we are calling a function called main,
0:13 and you can see that you call it with the parenthesis on the end some languages have semicolons to indicate the end of a line,
0:21 thankfully, Python does not have that, and this takes no arguments and it returns no value so you just call like this.
0:28 Now, the input on the other hand, we can call it and we pass it a string, kind of like print, but then it returns whatever the user inputted.
0:36 So we are to create a variable called saying, we are storing the return value from the input function
0:43 which is what the user typed in the saying variable we can work with that later. So that brings us to variables.
0:50 And variables in Python are very very simple, they are sort of no-nonsense, so you just say the name, or the word you want to use for the variable
0:57 and then you assign to it and... SHAZAM!! the variable exists. Some languages you have to specify types and initialization and so on,
1:04 Python is sort of as simple as it can be around variables. So here we have a variable called name, and we are assigning the value of Michael,
1:13 we have a variable called age and we are assigning 42, and we can even increment this value of the age, we are doing a "+=" operations,
1:21 so we are taking the age, adding 1 to it, now the age is 43, so happy birthday to me. We have more complex variables of course,
1:28 here we are creating what is called the list and we are populating the list with 3 strings, so biking, motocross and programming,
1:35 and then we are storing that list holding those objects in the hobbies. So, all of these are directly created upon assignment,
1:43 we can also create variables and store return values from functions, so here we have home address and we call in a function
1:48 and we are storing the result of that function into home address. So let's go back and use these ideas to finish up our "Hello World" app.