如何通過python打開文件

Question

我對編程和python語言非常陌生。

我知道如何在python中打開文件，但問題是如何打開文件作爲函數的參數？

例如：

function(parameter) 

這裏是我已經寫了代碼：

def function(file): 
    with open('file.txt', 'r') as f: 
     contents = f.readlines() 
    lines = [] 
    for line in f: 
     lines.append(line) 
    print(contents)  

Answer 1

您可以輕鬆地傳遞文件對象。

with open('file.txt', 'r') as f: #open the file 
    contents = function(f) #put the lines to a variable. 

，並在你的函數，返回行

def function(file): 
    lines = [] 
    for line in f: 
     lines.append(line) 
    return lines 

另一個竅門的列表，Python文件對象實際上有讀取文件的行的方法。像這樣：

with open('file.txt', 'r') as f: #open the file 
    contents = f.readlines() #put the lines to a variable (list). 

使用第二種方法，readlines就像你的功能。您不必再次調用它。

更新 這裏是你應該怎麼寫代碼：

第一種方法：

def function(file): 
    lines = [] 
    for line in f: 
     lines.append(line) 
    return lines 
with open('file.txt', 'r') as f: #open the file 
    contents = function(f) #put the lines to a variable (list). 
    print(contents) 

第二個：

with open('file.txt', 'r') as f: #open the file 
    contents = f.readlines() #put the lines to a variable (list). 
    print(contents) 

希望這有助於！

Answer 2

Python允許把多個打開的（）語句在一個單一的與。你用逗號分開它們。您的代碼將是：

def filter(txt, oldfile, newfile): 
    '''\ 
    Read a list of names from a file line by line into an output file. 
    If a line begins with a particular name, insert a string of text 
    after the name before appending the line to the output file. 
    ''' 

    with open(newfile, 'w') as outfile, open(oldfile, 'r', encoding='utf-8') as infile: 
     for line in infile: 
      if line.startswith(txt): 
       line = line[0:len(txt)] + ' - Truly a great person!\n' 
      outfile.write(line) 

# input the name you want to check against 
text = input('Please enter the name of a great person: ')  
letsgo = filter(text,'Spanish', 'Spanish2') 

而且不，你不會在你的函數的末尾加一個明確的返回來獲得任何東西。你可以使用return來儘早退出，但最後你會得到它，並且沒有它，函數將退出。 （當然，如果函數返回一個值，則使用return來指定要返回的值。）

Answer 3

def fun(file): 
    contents = None 

    with open(file, 'r') as fp: 
     contents = fp.readlines() 

    ## if you want to eliminate all blank lines uncomment the next line 
    #contents = [line for line in ''.join(contents).splitlines() if line] 

    return contents 

print fun('test_file.txt') 

或者你甚至可以修改此，這種方式需要的文件對象作爲函數arguement以及

Answer 4

def main(): 
     file=open("chirag.txt","r") 
     for n in file: 
       print (n.strip("t")) 
     file.close() 
if __name__== "__main__": 
     main() 


the other method is 


with open("chirag.txt","r") as f: 
     for n in f: 
       print(n)