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This article is to share with you about how to transfer exec and eval strings to python in Python. The editor thinks it is very practical, so I share it with you. I hope you can get something after reading this article.

Key points of knowledge:

1. Master random numbers and guess numbers Mini Game

2. Master the use of class random

3. Master multi-condition judgment and use the keywords and and or

The following begins with a textual explanation:

I. trial of exec function

The format that exec executes:

Exec (string)

After the string executed by exec is converted into python statement, it will be memorized in memory.

For example, execute the code:

> exec ("axi10")

> > a

ten

Use this function to make a typical case: gui's calculator

2. Object representation in Python

Use curly braces in English to indicate {}

Object representation, which is in the form of a key-value pair.

An example represents an object:

Person= {"name": "Liu Jinyu", sex: "male"}

Object in combination with the exec function to pass a value:

> exec ("print ('name:' + name+' gender:'+ sex)", person)

Name: Lao Liu gender: male

III. Interpretation of parameters

1.exec function

Two parameters of exec

Form 1: exec (string, an object that acts as a local protection)

Form 2: exec (string, an object that passes a value to a variable of the same name in a string)

The solution adopted when there is a namespace conflict

1), the way to use the full namespace, such as

> random.randint (1pc20)

nineteen

2) use an object to protect the namespace

> exec ("x=randint (1J 20)", s)

Passing values of three parameters of exec

Exec (string, an object that protects locally, an object that passes a value to a variable of the same name in a string)

> t = {"a": 1, "b": 3}

> exec ("print (aquib)", sPerry t)

four

2.eval function

The execution effect of this function is similar to the exec function

The Eval function returns the result of an execution, which we can save.

> x=eval ("1")

> > x

one

> x=eval ("aquib", smenet)

> > x

four

Case writing:

Enter the code and convert it directly to python for operation until the programming is completed and the result is returned.

IV. Summary and emphasis

1. Exec function executes string to python

2. Eval function executes string to Python

3. The similarities and differences between exec and eval functions.

4. The definition method of object

5. The use of exec function and eval function with multiple parameters.

The knowledge source code of this section:

CodesAll= "" print ("you can enter the python code. If you enter ljyok, it means that the input is finished, start execution") while True: x=input (") if x code =" ljyok ": print ("-start executing the code and output the result-") exec (codesAll) break else: codesAll+=x+"\ n "

The above is how to convert exec and eval strings to python in Python. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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