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• Letters in upper or lowercase like A to Z or a to z
• Special symbols like $, %, ^, &, *, (), @, !, etc.
• Whitespaces like spacebar, Tab key or Enter key
• ASCII or UNICODE characters like emoji symbols or other symbols with unique code.
Statements in Python
Instructions written in source code that are executed by a Python interpreter are called statements. There are
three types of statements in Python which are simple statements, multiline statements and multiple statements.
Let us learn about them in detail.
Simple Statements
By default, the end of a statement is done by pressing an Enter key. Each statement is written on a new line.
a=5 # is a simple statement where variable 'a' is created with value 5.
c=a + b
Multiline Statements
We can make a statement that extends over multiple lines. There are number of ways of making multiline
statement. Few are given below:
1. a = 4 + 5 +\
6 + 7 +\
8 + 9
\backslash helps you fit long calculations on multiple lines.
2. flowers =['Rose','Lily',
'Sunflower','Hebiscus']
3. marks =(10,25,16,
18,28,30)
Multiple Statements
Multiple statements represent more than one statement in a single line. This can be done by separating the
statements using semicolon (;).
a = 5; b = 10; c = a + b; print(c)
Tokens
Tokens are the smallest meaningful unit of a program. Python supports the following tokens:
• Keywords • Identifiers • Literals • Punctuators • Operators
Let us discuss each of these in detail.
Keywords
Keywords in Python are predefined and reserved words with special meanings and purposes and are not allowed
to be used as identifiers. We can see the list of the reserved keywords by giving the following command at the
Python command prompt:
>>>import keyword
>>>keyword.kwlist
226 Artificial Intelligence Play (Ver 1.0)-IX

