To je StringIO modul je objekt nalik datoteci u memoriji. Može se koristiti za unos ili izlaz većine funkcija koje korisnici mogu očekivati od običnog datotečnog objekta. Nakon što korisnik stvori StringIO objekte, on se inicijalno stvara davanjem niza konstruktoru. Ako nema niza, StringIO će biti prazan. U oba slučaja, početno prikazan kursor na datoteci počet će od nule.
Modul nije dostupan u najnovijoj verziji Pythona; stoga, da bismo mogli koristiti ovaj modul, moramo ga prenijeti u Io modul u Pythonu u obliku io.StringIO.
kako pretvoriti char u string
Primjer:
# 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())
Izlaz:
This is the initialized string. The file of the string after writing in it is: This is the initialized string. Welcome to Javatpoint.com.
Važne metode StringIO:
Slijede neke metode StringIO:
1. StringIO.getvalue(): Ova funkcija se koristi za vraćanje cijelog sadržaja datoteke.
Sintaksa:
Sintaksa gornje metode je:
File_name.getvalue()
Primjer:
# 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())
Izlaz:
Hello and thank you for visiting to Javatpoint.com
2. U ovome ćemo pogledati neke od funkcija StringIO koje vraćaju Booleovu vrijednost, tj. lažnu ili istinitu:
Sintaksa:
Sintaksa gornje metode je:
1. File_name.isatty() 2. File_name.readable() 3. File_name.writable() 4. File_name.seekable() 5. File_name.closed
Primjer:
lateks matrica
# 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)
Izlaz:
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 tražiti() funkcija se koristi za postavljanje položaja kursora unutar datoteke. Ako izvršimo bilo koju operaciju pisanja ili čitanja na dokumentu, kursor se postavlja na indeks koji je posljednji korišten tako da možemo pomaknuti kursor s početne pozicije datoteke seek() koja se koristi.
Sintaksa:
Sintaksa gornje metode je:
File_name.seek(argument) #This argument tells the function where to place the cursor.
Primjer:
# 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
Izlaz:
Hello and thank you for visiting to Javatpoint.com. Hello and thank you for visiting to Javatpoint.com.
4. StringIO.truncate(): Ova se funkcija koristi za promjenu veličine toka datoteke. Ova metoda sprema datoteku i ispušta je nakon zadanog indeksa.
Sintaksa:
Sintaksa gornje metode je:
File_name.truncate(size = None) # The user can provide the size from where to truncate the file.
Primjer:
niz.sadrži java
# 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())
Izlaz:
Hello and welcome to Javatpoint.com. Hello and welc
5. StringIO.tell(): Ova se metoda koristi za određivanje trenutnog toka datoteke i položaja kursora.
uključiti java
Sintaksa:
Sintaksa gornje metode je:
File_name.tell()
Primjer:
# 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())
Izlaz:
0 23
6. StringIO.close() Ovo se koristi za zatvaranje datoteke. Ova se funkcija poziva na datoteku i ne možemo izvršiti nikakve operacije na njoj. Svaka operacija koja se izvrši će rezultirati a ValueError .
Sintaksa: =
Sintaksa gornje metode je:
File_name.close(
Primjer:
# 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)
Izlaz:
Hello and welcome to Javatpoint.com. Is the file closed? True