#4 Python Tutorial for Beginners | Variables in Python
Telusko
Welcome back, aliens!
My name is Devin 20 and in this series on Python, we've covered what Python is,
installed software, and worked with operations. In this video, we'll be discussing
variables.
What is a Variable?
A variable is a container where you can store values. For example, we can store 2 in a
variable called "x".
Variables are useful because they allow us to change the value of the container, and we
can use them in operations. For instance, if we have x = 2 and y = 3, we can add them
together: x + y = 5.
Variables can store different types of values, such as integers and strings. We don't
need to define the type of the variable since it automatically takes the value of whatever
we assign to it.
Using Variables in Operations
We can use variables in operations just like we do with numbers. For example, we can
change the value of x from 2 to 9.
, We can also use underscores to represent the output of the previous operation. For
example, if we add x + 10, we can use the output of that operation (19) in another
operation: 19 + y = 22.
We can also fetch individual characters from a string stored in a variable using square
brackets. The numbering of characters starts at 0. For example, the first character of
"youtube" is "y" and the last character is "e". We can also use negative numbers to start
counting from the end of the string.
Working with Strings in Python
Let's start by looking at how to access specific characters in a string using index values:
● To access the first character, we use index 0.
● To access the second character, we use index 1, and so on.
● We can also use a colon to access a range of characters. For example, 0:2
will give us the first two characters.
It's important to note that the ending value in a range is exclusive, meaning it will not be
included in the result. If we want to access the first three characters, we would use 0:3.
If we don't specify an ending value, the range will go until the end of the string.
If we specify an ending value but not a starting value, the range will start at the
beginning of the string.
If we try to access characters outside the range of the string, we will get an error.
While strings in Python are immutable, meaning we cannot change individual
characters, we can concatenate strings and print them out in different ways.
We can also use the built-in len() function to find the length of a string.
Telusko
Welcome back, aliens!
My name is Devin 20 and in this series on Python, we've covered what Python is,
installed software, and worked with operations. In this video, we'll be discussing
variables.
What is a Variable?
A variable is a container where you can store values. For example, we can store 2 in a
variable called "x".
Variables are useful because they allow us to change the value of the container, and we
can use them in operations. For instance, if we have x = 2 and y = 3, we can add them
together: x + y = 5.
Variables can store different types of values, such as integers and strings. We don't
need to define the type of the variable since it automatically takes the value of whatever
we assign to it.
Using Variables in Operations
We can use variables in operations just like we do with numbers. For example, we can
change the value of x from 2 to 9.
, We can also use underscores to represent the output of the previous operation. For
example, if we add x + 10, we can use the output of that operation (19) in another
operation: 19 + y = 22.
We can also fetch individual characters from a string stored in a variable using square
brackets. The numbering of characters starts at 0. For example, the first character of
"youtube" is "y" and the last character is "e". We can also use negative numbers to start
counting from the end of the string.
Working with Strings in Python
Let's start by looking at how to access specific characters in a string using index values:
● To access the first character, we use index 0.
● To access the second character, we use index 1, and so on.
● We can also use a colon to access a range of characters. For example, 0:2
will give us the first two characters.
It's important to note that the ending value in a range is exclusive, meaning it will not be
included in the result. If we want to access the first three characters, we would use 0:3.
If we don't specify an ending value, the range will go until the end of the string.
If we specify an ending value but not a starting value, the range will start at the
beginning of the string.
If we try to access characters outside the range of the string, we will get an error.
While strings in Python are immutable, meaning we cannot change individual
characters, we can concatenate strings and print them out in different ways.
We can also use the built-in len() function to find the length of a string.
