What is the eval function in python

The eval() function is used to execute a string expression and return the value of the expression.

Syntax:

eval(expression[, globals[, locals]])

Parameters:

expression -- Expression.

globals -- Variable scope, global namespace, if provided, must be a dictionary object.

locals -- Variable scope, local namespace, if provided, can be any mapping object.

Example:

>>>x = 7
>>> eval( '3 * x' )
21
>>> eval('pow(2,2)')
4
>>> eval('2 + 2')
4
>>> n=81
>>> eval("n + 4")
85

The role of the eval() function in Python:

1. Convert characters to lists:

a = "[[1,2], [3,4], [5,6], [7,8], [9,0]]"
print(type(a)) 
b = eval(a)print(type(b))
print(b)

2. Convert string to dictionary

a = "{1: 'a', 2: 'b'}"
print(type(a))b = eval(a)
print(type(b))
print(b)

3. Convert character to tuple

a = "([1,2], [3,4], [5,6], [7,8], (9,0))"
print(type(a))b=eval(a)
print(type(b))
print(b)

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