Files Built in Methods

 

File Built In Methods

• close() : Closes the file.

 #program

 file = open("my_file_1.txt", "r")
 print(file.read())

 file.close()

 print("\nfile closed")

 #output

 Techno Xpresss.
 line-2
 line-3
 line-4
 line-5

 file closed

• if try to access file once closed.

 #program

 file = open("my_file_1.txt", "r")
 data = file.read()

 print(data)
 file.close()
 print("\nfile closed")

 data.file.read()    #trying to read file once closed

 #output

 Techno Xpresss.
 line-2
 line-3
 line-4
 line-5

 file closed
 Traceback (most recent call last):
   File "C:/Self_Practice_Er_M_S_Dandyan/Python/Pycharm/xml/main.py", line 58, in <module>
     data.file.read()
 AttributeError: 'str' object has no attribute 'file'

• detach() : Returns the separated raw stream from the buffer.

• fileno() : Returns a number that represents the stream, from the operating system's perspective.

• flush() : Flushes the internal buffer.

 #program

 file = open("my_file_1.txt", "r")
 data = file.read()
 print(data)

 file.flush()
 print("After Flushing")
 data = file.read()
 print(data)
 file.close()
 

 #output

 Techno Xpresss.
 line-2
 line-3
 line-4
 line-5

 After Flushing

• isatty() : Returns whether the file stream is interactive or not.

• read() : Returns the file content.

 #program

 file = open("my_file_1.txt", "r")

 data = file.read()
 print(data)
 file.close()

 #output

 Techno Xpresss.
 line-2
 line-3
 line-4
 line-5

• readable() : Returns whether the file stream can be read or not.

 #program

 file = open("my_file_1.txt", "r")
 readable = file.readable()
 print("my_file_1.txt is readable : ", readable)
 file.close()

 #output

 my_file_1.txt is readable :  True

• readline() : Returns one line from the file.
• it will read one line from the time 

 #program

 file = open("my_file_1.txt", "r")
 data = file.readline()
 print(data)
 data = file.readline()
 print(data)
 data = file.readline()
 print(data)
 file.close()

 #output

 Techno Xpresss.

 line-2

 line-3

• readlines(): Returns a list of lines from the file.

 #program

 file = open("my_file_1.txt", "r")
 data = file.readlines()
 print(data)

 for x in data :
     print(x)

 file.close()

 #output

 ['Techno Xpresss.\n', 'line-2\n', 'line-3\n', 'line-4\n', 'line-5\n']
 Techno Xpresss.

 line-2

 line-3

 line-4

 line-5

• seek() : Change the file position.

 #program

 file = open("my_file_1.txt", "r")
 data = file.read()
 print(data)

 file.seek(5)
 data = file.read()
 print(data)

 file.seek(12)
 data = file.read()
 print(data)

 file.close()

 #output

 Hi, this is Techno Xpresss.

 his is Techno Xpresss.

 Techno Xpresss.

• seekable() : Returns whether the file allows us to change the file position.

 #program

 file = open("my_file_1.txt", "r")
 data = file.read()
 print(data)

 seekable = file.seekable()
 print("my_file_1.txt is seekable : ", seekable)

 file.close()

 #output

 Hi, this is Techno Xpresss.

 my_file_1.txt is seekable :  True

• tell() : Returns the current file position.

 #program

 file = open("my_file_1.txt", "r")
 data = file.read()
 print(data)

 position = file.tell()
 print("current position index : ", position)

 file.seek(0)
 position = file.tell()
 print("current position index : ", position)
 file.close()

 #output

 Hi, this is Techno Xpresss.

 current position index :  29
 current position index :  0

• truncate() : Resizes the file to a specified size.

• writable() : Returns whether the file can be written to or not.

 #program

 file = open("my_file_1.txt", "r")
 data = file.read()
 print(data)

 writable = file.writable()
 print("cmy_file_1.txt is writable if opened in read mode   : ", writable)
 file.close()

 file = open("my_file_1.txt", "a")
 writable = file.writable()
 print("cmy_file_1.txt is writable if opened in append mode : ", writable)
 file.close()

 #output

 Hi, this is Techno Xpresss.

 cmy_file_1.txt is writable if opened in read mode   :  False
 cmy_file_1.txt is writable if opened in append mode :  True

• write() : Writes the specified string to the file.

 #program

 file = open("my_file.txt", "r")
 file_1 = open("my_file_1.txt", "w")
 data = file.read()
 print("data read successfully\n")
 print(data)
 file_1.write(data)
 print("\ndata written successfully")

 file.close()

 #output

 data read successfully

 Hi, this is Techno Xpresss.
 This is a sample file.

 data written successfully

• writelines(): Writes a list of strings to the file.

 #program

 file = open("my_file.txt", "r")
 file_1 = open("my_file_1.txt", "w")
 data = file.readlines()
 print(data)
 file_1.writelines(data)

 file.close()
 file_1.close()

 file = open("my_file_1.txt", "r")
 data = file.read()
 print(data)

 #output

 ['Hi, this is Techno Xpresss.\n', 'This is a sample file.\n', 'Hope you all are doing well.']
 Hi, this is Techno Xpresss.
 This is a sample file.
 Hope you all are doing well.