Operators are used to performing operations on variables and values. In the example below, we use the + operator to add together two values: Example print(10 + 5) Output:15 Python divides the operators into 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… Read More »
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: Example print(10 > 9)print(10 == 9)print(10 < 9) Output:TrueFalseFalse When you run a condition… Read More »
Python has a set of built-in methods that you can use on strings. Note: All string methods returns new values. They do not change the original string. Example Upper case the first letter in this sentence:txt = “hello, and welcome to my world.”x = txt.capitalize()print (x) Output:Hello, and welcome to my world. Method Syntax Description capitalize() string.capitalize() Converts… Read More »
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… Read More »
As we learned in the Python Variables chapter, we cannot combine strings and numbers like this: Example age = 36txt = “My name is John, I am ” + ageprint(txt) Output:Traceback (most recent call last): File “demo_string_format_error.py”, line 2, in <module> txt = “My name is John, I am ” + ageTypeError: must be str, not int But we can… Read More »
To concatenate, or combine, two strings you can use the + operator. Example Merge variable a with variable b into variable c:a = “Hello”b = “World”c = a + bprint(c) Output:HelloWorld Example To add a space between them, add a ” “:a = “Hello”b = “World”c = a + ” ” + bprint(c) Output:Hello World
Python has a set of built-in methods that you can use on strings. Upper Case Example The upper() method returns the string in upper case:a = “Hello, World!”print(a.upper()) Output:HELLO, WORLD! Lower Case Example The lower() method returns the string in lower case:a = “Hello, World!”print(a.lower()) Output:hello, world! Remove Whitespace Whitespace is the space before and/or after the actual text, and very… Read More »
You can return a range of characters by using the slice syntax. Specify the start index and the end index, separated by a colon, to return a part of the string. Example Get the characters from position 2 to position 5 (not included):b = “Hello, World!”print(b[2:5]) Output:llo Note: The first character has index 0. Slice From the… Read More »
Strings in python are surrounded by either single quotation marks, or double quotation marks. ‘hello’ is the same as “hello”. You can display a string literal with the print() function: Example print(“Hello”)print(‘Hello’) Output:HelloHello Assign String to a Variable Assigning a string to a variable is done with the variable name followed by an equal sign and the string: Example… Read More »
Specify a Variable Type There may be times when you want to specify a type on to a variable. This can be done with casting. Python is an object-orientated language, and as such it uses classes to define data types, including its primitive types. Casting in python is therefore done using constructor functions: int() – constructs… Read More »