É o StringIO módulo é um objeto semelhante a um arquivo na memória. Ele pode ser usado para inserir ou gerar a maioria das funções que os usuários podem esperar de um objeto de arquivo comum. Depois que o usuário cria os objetos StringIO, ele é inicialmente criado fornecendo uma string ao construtor. Se não houver string, StringIO estará vazio. Em ambos os casos, o cursor exibido inicialmente no arquivo começará em zero.
O módulo não está disponível na versão mais recente do Python; portanto, para podermos usar este módulo, precisamos transferi-lo para o módulo Io em Python na forma de io.StringIO.
convenção de nomenclatura para java
Exemplo:
# 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())
Saída:
This is the initialized string. The file of the string after writing in it is: This is the initialized string. Welcome to Javatpoint.com.
Métodos importantes de StringIO:
A seguir estão alguns métodos de StringIO:
1.StringIO.getvalue(): Esta função é usada para retornar todo o conteúdo do arquivo.
Sintaxe:
A sintaxe do método acima é:
File_name.getvalue()
Exemplo:
# 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())
Saída:
Hello and thank you for visiting to Javatpoint.com
2. Neste artigo, veremos algumas das funções de StringIO que retornam um valor booleano, ou seja, falso ou verdadeiro:
Sintaxe:
A sintaxe do método acima é:
1. File_name.isatty() 2. File_name.readable() 3. File_name.writable() 4. File_name.seekable() 5. File_name.closed
Exemplo:
divisão de string java
# 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)
Saída:
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(): O procurar() A função é usada para definir a posição do cursor dentro do arquivo. Se executarmos qualquer operação de gravação ou leitura em um documento, o cursor é colocado no índice que foi usado pela última vez para que possamos mover o cursor da posição inicial do arquivo que seek() é empregado.
Sintaxe:
A sintaxe do método acima é:
File_name.seek(argument) #This argument tells the function where to place the cursor.
Exemplo:
# 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
Saída:
Hello and thank you for visiting to Javatpoint.com. Hello and thank you for visiting to Javatpoint.com.
4.StringIO.truncate(): Esta função é usada para redimensionar o tamanho do fluxo de arquivos. Este método salva o arquivo e o descarta após o índice fornecido.
Sintaxe:
A sintaxe do método acima é:
File_name.truncate(size = None) # The user can provide the size from where to truncate the file.
Exemplo:
listas 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())
Saída:
Hello and welcome to Javatpoint.com. Hello and welc
5.StringIO.tell(): Este método é usado para informar o fluxo atual do arquivo e a posição do cursor.
sistema operacional linux
Sintaxe:
A sintaxe do método acima é:
File_name.tell()
Exemplo:
# 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())
Saída:
0 23
6.StringIO.close() Isso é usado para fechar o arquivo. Esta função é chamada em um arquivo e não podemos realizar nenhuma operação nele. Qualquer operação realizada resultará em um Erro de valor .
Sintaxe: =
A sintaxe do método acima é:
File_name.close(
Exemplo:
# 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)
Saída:
Hello and welcome to Javatpoint.com. Is the file closed? True