Det er den StringIO modul er et fillignende objekt i minnet. Den kan brukes til å legge inn eller skrive ut de fleste funksjonene brukere kan forvente fra et vanlig filobjekt. Når brukeren oppretter StringIO-objektene, opprettes de først ved å gi en streng til konstruktøren. Hvis det ikke er noen streng, vil StringIO være tom. I begge tilfeller vil den opprinnelig viste markøren på filen starte på null.
Modulen er ikke tilgjengelig i den nyeste versjonen av Python; For å kunne bruke denne modulen må vi derfor overføre den til Io-modulen i Python i form av io.StringIO.
Eksempel:
alfabetet nummer
# 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())
Produksjon:
This is the initialized string. The file of the string after writing in it is: This is the initialized string. Welcome to Javatpoint.com.
Viktige metoder for StringIO:
Følgende er noen metoder for StringIO:
1. StringIO.getvalue(): Denne funksjonen brukes til å returnere hele innholdet i filen.
Syntaks:
Syntaksen for metoden ovenfor er:
File_name.getvalue()
Eksempel:
# 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())
Produksjon:
Hello and thank you for visiting to Javatpoint.com
2. I dette ser vi på noen av funksjonene til StringIO som returnerer en boolsk verdi, dvs. enten usann eller sann:
Syntaks:
hva er svn checkout
Syntakser for metoden ovenfor er:
1. File_name.isatty() 2. File_name.readable() 3. File_name.writable() 4. File_name.seekable() 5. File_name.closed
Eksempel:
# 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)
Produksjon:
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(): De søke() funksjonen brukes til å angi markørens posisjon i filen. Hvis vi utfører en skrive- eller leseoperasjon på et dokument, plasseres markøren på indeksen som sist ble brukt, slik at vi kan flytte markøren fra startposisjonen til filen seek() er brukt.
Syntaks:
Syntaksen for metoden ovenfor er:
File_name.seek(argument) #This argument tells the function where to place the cursor.
Eksempel:
# 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
Produksjon:
hvis annet bash
Hello and thank you for visiting to Javatpoint.com. Hello and thank you for visiting to Javatpoint.com.
4. StringIO.truncate(): Denne funksjonen brukes til å endre størrelsen på filstrømmen. Denne metoden lagrer filen og slipper den etter den gitte indeksen.
Syntaks:
Syntakser for metoden ovenfor er:
rekursjon java
File_name.truncate(size = None) # The user can provide the size from where to truncate the file.
Eksempel:
# 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())
Produksjon:
Hello and welcome to Javatpoint.com. Hello and welc
5. StringIO.tell(): Denne metoden brukes til å fortelle filens gjeldende strøm og markørposisjon.
Syntaks:
Syntakser for metoden ovenfor er:
File_name.tell()
Eksempel:
# 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())
Produksjon:
0 23
6. StringIO.close() Dette brukes til å lukke filen. Denne funksjonen kalles på en fil, og vi kan ikke utføre noen operasjoner på den. Enhver operasjon som utføres vil resultere i en ValueError .
Syntaks: =
Syntakser for metoden ovenfor er:
File_name.close(
Eksempel:
junitprøvetilfeller
# 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)
Produksjon:
Hello and welcome to Javatpoint.com. Is the file closed? True