爲什麼sys.stdout.write不能在python2中工作？

Question

#!/usr/bin/python 
import sys 

def main(): 

    f=open("a",'r') 
    line1=f.readlines() 
    f.close() 

    try: 
     sys.stdout.write(line1) 
    except: 
     print "?" 
if __name__ == "__main__": 
    main() 

Answer 1

f.readlines()不返回單個字符串，它返回列表。即使只有一條線！所以sys.stdout.write()不知道如何處理。如果遍歷該行列表，並嘗試寫入每一行，那麼它工作得很好：

#!/usr/bin/python 
import sys 

def main(): 

    f = open("a",'r') 
    lines = f.readlines() # lines is actually a list 
    f.close() 

    print lines # You'll see your issue, here! 
    try: 
     for line in lines: 
      sys.stdout.write(line) # Works now 
    except: 
     print "?" 

if __name__ == "__main__": 
    main()