Loop Through a List
You can loop through the list items by using a for loop:
Example
Print all items in the list, one by one:
thislist = ["apple", "banana", "cherry"]
for x in thislist:
print(x)
Category: Python
Python – Remove List Items
Remove Specified Item
The remove() method removes the specified item.
Example
Remove “banana”:
thislist = ["apple", "banana", "cherry"]
thislist.remove("banana")
print(thislist)
If there are more than one item with the specified value, the remove() method removes the first occurrence: Continue reading Python – Remove List Items
Python – Add List Items
Append Items
To add an item to the end of the list, use the append() method:
Example
Using the append() method to append an item:
thislist = ["apple", "banana", "cherry"]
thislist.append("orange")
print(thislist)
Insert Items
To insert a list item at a specified index, use the insert() method.
The insert() method inserts an item at the specified index: Continue reading Python – Add List Items
Python – Change List Items
Change Item Value
To change the value of a specific item, refer to the index number:
Example
Change the second item:
thislist = ["apple", "banana", "cherry"]
thislist[1] = "blackcurrant"
print(thislist)
Change a Range of Item Values
To change the value of items within a specific range, define a list with the new values, and refer to the range of index numbers where you want to insert the new values: Continue reading Python – Change List Items
Python – Access List Items
Access Items
List items are indexed and you can access them by referring to the index number:
Example
Print the second item of the list:
thislist = ["apple", "banana", "cherry"]
print(thislist[1])
Note: The first item has index 0.
Negative Indexing
Negative indexing means start from the end
-1 refers to the last item, -2 refers to the second last item etc. Continue reading Python – Access List Items
Python Lists
mylist = ["apple", "banana", "cherry"]
List
Lists are used to store multiple items in a single variable.
Lists are one of 4 built-in data types in Python used to store collections of data, the other 3 are Tuple, Set, and Dictionary, all with different qualities and usage.
Lists are created using square brackets: Continue reading Python Lists
Python Operators
Python Operators
Operators are used to perform operations on variables and values.
In the example below, we use the + operator to add together two values:
Example
print(10 + 5)
Python divides the operators in the following groups:
- Arithmetic operators
- Assignment operators
- Comparison operators
- Logical operators
- Identity operators
- Membership operators
- Bitwise operators
Python Arithmetic Operators
Arithmetic operators are used with numeric values to perform common mathematical operations: Continue reading Python Operators
Python Booleans
Booleans represent one of two values: True or False.
Boolean Values
In programming you often need to know if an expression is True or False.
You can evaluate any expression in Python, and get one of two answers, True or False.
When you compare two values, the expression is evaluated and Python returns the Boolean answer: Continue reading Python Booleans
Python – String Methods
String Methods
Python has a set of built-in methods that you can use on strings.
Note: All string methods return new values. They do not change the original string.
Python – Escape Characters
Escape Character
To insert characters that are illegal in a string, use an escape character.
An escape character is a backslash \ followed by the character you want to insert.
An example of an illegal character is a double quote inside a string that is surrounded by double quotes:
Example
You will get an error if you use double quotes inside a string that is surrounded by double quotes:
txt = "We are the so-called "Vikings" from the north."
To fix this problem, use the escape character \": Continue reading Python – Escape Characters