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This article mainly introduces how to use the eval() function in python. The introduction in the article is very detailed and has certain reference value. Interested friends must read it!

What is the eval() function?

A Python built-in function;

Returns the expression result of the incoming string (official)

Eval() function syntax analysis

3. eval() function application example 3.1 eval() basic application example

The above example shows three applications of eval():

Convert a string to a code expression and find the result, such as 66+72

Convert strings to other data types, such as dictionaries, lists, tuples, sets, etc.

Pass the globals parameter and the locations parameter. When both parameters exist, look for the locations parameter first and then the globals parameter. The variable with the same name in the locations parameter will overwrite the variable in globals.

3.2 eval() Examples of hazards

In the above example, eval() converts a string into an expression and executes it, which can be used to execute system commands, delete files, etc.

3.3 ast.literal_eval() replaces eval() for data type conversion

The above code can also perform type conversion, but because eval() is not used, it creates less security risk.

literal_eval() function: it will determine whether the content to be calculated is a legal python type after calculation, if it is, it will be operated, otherwise it will not be operated.

The above is "how to use eval() function in python" all the contents of this article, thank you for reading! Hope to share the content to help everyone, more relevant knowledge, welcome to pay attention to the industry information channel!

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