Tas ir StringIO modulis ir failam līdzīgs objekts atmiņā. To var izmantot, lai ievadītu vai izvadītu lielāko daļu funkciju, ko lietotāji var sagaidīt no parasta faila objekta. Kad lietotājs ir izveidojis StringIO objektus, tas sākotnēji tiek izveidots, nodrošinot virkni konstruktoram. Ja nav virknes, StringIO būs tukšs. Abos gadījumos sākotnēji parādītais kursors failā sāksies ar nulli.
Modulis nav pieejams jaunākajā Python versijā; tādējādi, lai varētu izmantot šo moduli, mums tas ir jāpārnes uz Io moduli Python formātā io.StringIO.
Piemērs:
# First, we will import the required module. from io import StringIO as SIO # The arbitrary string. string_1 = 'This is the initialized string.' # Here, we will use the StringIO method for setting as the file object. # Now, we have an object-file that we can treat as a file. file_1 = SIO(string_1) # Now, we will be reading the file by using read() print (file_1.read()) # Here, We can also write in this file. file_1.write(' Welcome to Javatpoint.com.') # by using the following command, we can make the cursor at index 0. file_1.seek(0) # by using the following command, the user is able to print the file after writing #in the initialized string (string_1). print ('The file of the string after writing in it is:', file_1.read())
Izvade:
javascript if paziņojums
This is the initialized string. The file of the string after writing in it is: This is the initialized string. Welcome to Javatpoint.com.
Svarīgas StringIO metodes:
Tālāk ir norādītas dažas StringIO metodes.
1. StringIO.getvalue(): Šī funkcija tiek izmantota, lai atgrieztu visu faila saturu.
Sintakse:
Iepriekš minētās metodes sintakse ir:
File_name.getvalue()
Piemērs:
# First, we will import the StringIO module. from io import StringIO as SIO # The arbitrary string. string_1 = 'Hello and thank you for visiting to Javatpoint.com.' # Here, we will use the StringIO method for setting as the file object. file_1 = SIO(string_1) # Retrieving the complete contents of the above file. print(file_1.getvalue())
Izvade:
java operatori
Hello and thank you for visiting to Javatpoint.com
2. Šeit mēs aplūkojam dažas StringIO funkcijas, kas atgriež Būla vērtību, t.i., vai nu false, vai true:
Sintakse:
Iepriekš minētās metodes sintakses ir šādas:
1. File_name.isatty() 2. File_name.readable() 3. File_name.writable() 4. File_name.seekable() 5. File_name.closed
Piemērs:
# First, we will import the StringIO module. from io import StringIO as SIO # The arbitrary string. string_1 = 'Hello and thank you for visiting to Javatpoint.com.' # Here, we will use the StringIO method for setting # as the file object. file_1 = SIO(string_1) # by using the following command, the user will be able to return is the file #interactive or not. print ('Is the file stream above interactive?', file_1.isatty()) # by using the following command, # the user will be able to return is the file readable or not. print ('Is the file stream above readable?', file_1.readable()) # by using the following command, # the user will be able to return does the file support writing or not. print ('Is the file stream above writable?', file_1.writable()) # by using the following command, , the user will be able to return is the file #seekable or not. print ('Is the file stream above seekable?', file_1.seekable()) # by using the following command, the user will be able to return is the file #closed or not. print ('Is the file above closed?', file_1.closed)
Izvade:
Is the file stream above interactive? False Is the file stream above readable? True Is the file stream above writable True Is the file stream above seekable? True Is the file above closed? False
3. StringIO.seek(): The meklēt () funkcija tiek izmantota, lai iestatītu kursora pozīciju failā. Ja mēs izpildām kādu rakstīšanas vai lasīšanas darbību dokumentā, kursors tiek novietots uz pēdējo izmantotā indeksa, lai mēs varētu pārvietot kursoru no faila sākuma pozīcijas, kurā tiek izmantots seek().
Sintakse:
Iepriekš minētās metodes sintakse ir:
java slēdzis int
File_name.seek(argument) #This argument tells the function where to place the cursor.
Piemērs:
# First, we will import the StringIO module. from io import StringIO as SIO # The arbitrary string. string_1 ='Hello and thank you for visiting to Javatpoint.com.' # Here, we will use the StringIO method for setting as the file object. file_1 = SIO(string_1) # here, the user will be able to Read the file: print (file_1.read()) #If the user wishes to view the file again, it will display empty file since the #cursor has been set to the last index. It will also not print anything because #the function returns an empty string. print (file_1.read()) # So, to set the cursor position for reading or writing the file again # we can use seek() function. #We can pass any index here form(0 to len(file)) file_1.seek(0) # Now the user can read the file again print (file_1.read())S
Izvade:
Hello and thank you for visiting to Javatpoint.com. Hello and thank you for visiting to Javatpoint.com.
4. StringIO.truncate(): Šī funkcija tiek izmantota, lai mainītu faila straumes lielumu. Šī metode saglabā failu un nomet to pēc norādītā indeksa.
Sintakse:
Iepriekš minētās metodes sintakses ir šādas:
File_name.truncate(size = None) # The user can provide the size from where to truncate the file.
Piemērs:
# First, we will import the StringIO module. from io import StringIO as SIO # The arbitrary string. string_1 ='Hello and welcome to Javatpoint.com.' # Here, we will use the StringIO method for setting as the file object. file_1 = SIO(string_1) # here, we can read the initial file: print(file_1.read()) # for setting the cursor at 0. file_1.seek(0) # for dropping the file after the given index, i.e., 14. file_1.truncate(14) # here, it will print the File after truncate. print(file_1.read())
Izvade:
Hello and welcome to Javatpoint.com. Hello and welc
5. StringIO.tell(): Šo metodi izmanto faila pašreizējās straumes un kursora pozīcijas noteikšanai.
Sintakse:
Iepriekš minētās metodes sintakses ir šādas:
File_name.tell()
Piemērs:
# First, we will import the StringIO module. from io import StringIO as SIO # The arbitrary string. string_1 ='Hello and welcome to Javatpoint.com.' # Here, we will use the StringIO method for setting as the file object. file_1 = SIO(string_1) # Here the cursor is set at index '0'. print(file_1.tell()) # now, we are setting the Cursor to index '23'. file_1.seek(23) # here, we will be printing the index of cursor print(file_1.tell())
Izvade:
0 23
6. StringIO.close() To izmanto, lai aizvērtu failu. Šī funkcija tiek izsaukta failā, un mēs ar to nevaram veikt nekādas darbības. Jebkura darbība, kas tiek veikta, izraisīs a ValueError .
Sintakse: =
Fredijs Merkūrijs
Iepriekš minētās metodes sintakses ir šādas:
File_name.close(
Piemērs:
# First, we will import the StringIO module. from io import StringIO as SIO # The arbitrary string. string_1 ='Hello and welcome to Javatpoint.com.' # Here, we will use the StringIO method for setting as the file object. file_1 = SIO(string_1) # here, we can read the initial file: print(file_1.read()) # for closing the current file. file_1.close() # If the user would perform any operation on the above file now, it will raise an #ValueError. # here, we will be using the closed function to know whether the file is closed #or not. print('Is the file closed?', file_1.closed)
Izvade:
Hello and welcome to Javatpoint.com. Is the file closed? True