1.11 Literal constants

Literal constants-

A literal is a sequence of one or more characters that stands for itself.

The numbers such as 2,51,100.12 are literal constant as value of its is constant.

Also strings such as “Welcome to Python tutorial” are also literal constants.

Numeric Literals

A numeric literal is a literal containing only the digits 0–9, an optional sign character (1 or 2), and a possible decimal point. (The letter e is also used in exponential notation, shown in the next

subsection). If a numeric literal contains a decimal point, then it denotes a floating-point value, or “float” (e.g., 10.24); otherwise, it denotes an integer value (e.g., 10). Commas are never used in numeric literals.

The numbers such as -2, +51, 100.12, -100.12

Limits of Range in Floating-Point Representation

There is no limit to the size of an integer that can be represented in Python. Floating-point values,

however, have both a limited range and a limited precision. Python uses a double-precision standard format (IEEE 754) providing a range of 10 2 308 to 10 308 with 16 to 17 digits of precision. To denote such a range of values, floating-points can be represented in scientific notation.

Arithmetic overflow occurs when a calculated result is too large in magnitude to be represented.

Arithmetic underflow occurs when a calculated result is too small in magnitude to be represented.

String Literals:

Numerical values are not the only literal values in programming. String literals, or “strings,” represent a sequence of characters,

'Hello' 'Smith, John' "Baltimore, Maryland 21210"

In Python, string literals may be delimited (surrounded) by a matching pair of either single (') or

double (") quotes. Strings must be contained all on one line (except when delimited by triple quotes). We have already seen the use of strings in Chapter 1 for displaying screen output,

... print ('Welcome to Python!')

Welcome to Python!