Python如果變量變量

Question

我做了一個文件叫helloworld.simon。 在那裏，我已經寫了：

Public class helloworld { 
main = (main.method()); 
main { 
    console.print("Hello World"); 
    } 

而且我寫了這個代碼：

Public = ("Public") 
Private = ("Private") 
code = open('helloworld.simon' , 'r') 
print(code.read()) 
if Public in code: 
    print("Pub") 
else: 
    print("J") 

和輸出是：

Public class helloworld { 
main = (main.method()); 
main { 
    console.print("Hello World"); 
    } 

J 

Answer 1

改變這一行：

code = open('helloworld.simon' , 'r')

要這樣：

with open('helloworld.simon' , 'r') as f: 
    lines = f.readlines() 
    if any([line for line in lines if Public in line]): 
     print("Pub") 
    else: 
     print("J") 

Answer 2

文件讀取是連續的。一旦你讀一個文件（print(code.read())你不能再回來讀，除非重新閱讀與code.seek(0)

Public = ("Public") 
Private = ("Private") 
code = open('helloworld.simon' , 'r') 
print(code.read()) 
code.seek(0) 
if Public in code.read(): 
    print("Pub") 
else: 
    print("J") 
code.close() 

輸出：

Pub 

如果你對此有何評論code.seek(0)，輸出Ĵ