phytonLet digit be [0-9] what does the following regular expressiondefines?
a).[-]?(({digit}+)|({digit}*.{digit}+)([eE][+-]?{digit}+)?)b). [-+]?{digit}+c). Give two examples for each of the above.
Solution
a)
The regular expression
[-]?(({digit}+)|({digit}*.{digit}+)([eE][+-]?{digit}+)?)
Defines a signed number or signed number represented inexponential form
where:
[-]? :stands for the sign which can be ‘-‘ ornothing.
({digit}+) : is used to denote the occurrence of oneor more digits cannot be empty hence ‘+’ sign is used.
{digit}* : denote the presence of zero or moredigits.
.{digit}+) : is used for representing one or morenumbers after the decimal point (.).
([eE][+-]?{digit}+) : denote the exponential parteither (‘e’ or ‘E’) and (‘+’ or