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  • Python进阶-pickle/eval/exec

    • 参考:
      •   eval/exec/compile的区别:https://stackoverflow.com/questions/2220699/whats-the-difference-between-eval-exec-and-compile-in-python
      •   pickle的使用: https://pythontips.com/2013/08/02/what-is-pickle-in-python/
    • 背景
      • 之前用打印到文件,逐行读出用eval转换格式。现在用pickle可直接实现。
    • pickle_eval_exec的区别:
      • pickle: dump到file, 从file中load
      • eval: eval accepts only a single expression, eval returns the value of the given expression。
      • exec: exec can take a code block that has Python statements: loops, try: except:class and function/method definitions and so on. return None.
    • Pickle的使用:(pickle.load(), pickle.dump())
    import pickle
    
    a = ['test value','test value 2','test value 3']
    a
    ['test value','test value 2','test value 3']
    
    file_Name = "testfile"
    # open the file for writing
    fileObject = open(file_Name,'wb') 
    
    # this writes the object a to the
    # file named 'testfile'
    pickle.dump(a,fileObject)   
    
    # here we close the fileObject
    fileObject.close()
    # we open the file for reading
    fileObject = open(file_Name,'r')  
    # load the object from the file into var b
    b = pickle.load(fileObject)  
    b
    ['test value','test value 2','test value 3']
    a==b
    True
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  • 原文地址:https://www.cnblogs.com/ryu-manager/p/9399453.html
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