Python output variable to file

Python how to save python output variableto file

We need to open the file in mode, which indicates read mode in binary files. Since it converts objects to byte-stream, we need to open the file in mode, which indicates write mode in binary files.

Python write variable to file

File handling is an important concept of programming. Python allows us to read and write content to an external file.

In this article, we will discuss several ways to write variable to file in Python.

• To write data to an external file, we first open the required file using the open() function. This creates the file object associated with the required file.
• We need to open it in write mode, so it is necessary to specify the mode as w in the open() function.
• We can also add the type of the file using t and b while specifying the mode. Here, t indicates a text file, and b indicates a binary file.
• To write content to this file, we will use the write() function with the file object. We pass the contents as a string.
• After writing the necessary data, we can close the file using the close() function.
• We can avoid this close function by using the with statement to open the file. The with statement makes the code more readable, avoids exceptions, and removes the need to close the file.

A variable is a simple object which holds data in the memory and can be of any type. For our examples, we will use a dictionary and write this dictionary to a file. We will convert this dictionary to a string using different methods.

Using the str() function

str() function is used to typecast a variable into a string. We can use this to convert the dictionary variable to a string and write it to a file.

The str() function returns the string representation of the dictionary and we write it to the required file.

Further reading:

Check if variable exists in Python

Print environment variables in Python

Using the repr() function

repr() function works similarly to the str() method for providing string representation of objects. However, it is unambiguous and is used generally for development and debugging processes. It gives the exact representation of the object and does not aim to make it readable, as is the case with the str() function.

For our purpose, although the result is the same, it is generally recommended to use this method over the str() function.

Using the string formatting

We can also use string formatting to convert the dictionary variable to a string before writing it to a file. The %s format can be used to make this conversion.

See the following example.

Using the pickle.dump() function

Pickling is a way to serialize and de-serialize objects. In Python, we can use the pickle module to convert objects to byte stream using the dump() function.

We can use this method to write variable to file in Python. Since it converts objects to byte-stream, we need to open the file in wb mode, which indicates write mode in binary files. We will use this dump() function in place of the write() function. We need to specify the file object and the variable to be written in this file as arguments in the dump() function.

The above example will write the dictionary d to the sample.txt file as bytes. Therefore if you open the text file you will find a sequence of byte characters. To verify the contents of the file, we can read it using the pickle.load object. We need to open the file in rb mode, which indicates read mode in binary files.

We will read the contents of this file in the following code.

Note that it is not advisable to read pickled data from unknown sources. This is because they may contain malware or malicious code.

Using the numpy.savetxt function

You can also use numpy library to write list variable to file in Python. We will create list and save the list to a text file named ‘sample.txt’.

1.000000000000000000e+01
2.000000000000000000e+01
3.000000000000000000e+01
4.000000000000000000e+01
5.000000000000000000e+01

Now in this article, we discussed different methods on how to write a variable to a file. We worked with file-handling examples and a dictionary, but for other objects, there may be simpler methods available.

For example, for numpy arrays, we can use the numpy.savetxt() to export an array to a text file. So bear in mind that there might be other methods available, but it depends on the variable type.

How do I save and restore multiple variables in python?, If you need to save multiple objects, you can simply put them in a single list, or tuple, for instance: import pickle # obj0, obj1, obj2 are created here.

Writing Data to a Text File in Python

Missing: variableto | Must include:

Print variable to txt file [duplicate]

Use open(file, mode) with the pathname of a file as file and mode as «w» to open the file for writing. Call file. write(data) with data as the string formats «%s %d» followed by % and a tuple containing a string of the variable name, and the variable. Hope this works!

file = open("fileName.txt","w") file.write(str(velocity) + "\n") file.close() 

«w» in line 1 means you are writing to the file. Adding «\n» means here is the end of the content.

How to save a variable to a text file and retrieve it later?

you can store your data as a json:

import json import os # data will be saved base on the account # each account will have one usernae and one pass PASS_FILE = 'password.json' def get_pass_json_data(): if os.path.isfile(PASS_FILE): with open(PASS_FILE) as fp: return json.load(fp) return <> def get_pass(): account = input("What account is this for?") data = get_pass_json_data() if account not in data: print('You do not have this account in the saved data!') else: print(data[account]) def savingPasswords(): username = input("Enter username") password = input ("Enter password") account = input("What account is this for?") data = get_pass_json_data() # this will update your pass and username for an account # if already exists data.update( < account: < 'username': username, 'password': password >>) with open(PASS_FILE, 'w') as fp: json.dump(data, fp) print ("Login successfully saved!") actions = < 'add': savingPasswords, 'get': get_pass >def display(): print("Do you want to add a password to get a password? get/add") action = input() try: actions[action]() except KeyError: print('Bad choice, should be "get" or "add"') while True: display() 

The problem was with your second function. I would advise using with open to open and write to files since it looks cleaner and it is easier to read. In your code you never wrote to the file or closed the file. The with open method closes the file for you after the indented block is executed. I would also recommend writing to something like a csv file for organized information like this so it will be easier to retrieve later.

def display(): response = input("Do you want to add a password to get a password? (get/add)\n") if response.upper() == "GET": get_password() elif response.upper() == "ADD": write_password() else: print("Command not recognized.") exit() def write_password(): with open("password.csv", "a") as f: username = input("Enter username: ") password = input("Enter password: ") account = input("What account is this for? ") f.write(f",,\n") # separates values into csv format so you can more easily retrieve values print("Login successfully saved!") def get_password(): with open("password.csv", "r") as f: username = input("What is your username? ") lines = f.readlines() for line in lines: if line.startswith(username): data = line.strip().split(",") print(f"Your password: \nYour Account type: ") while True: display() 

password="my_secret_pass" with open("password.txt","w") as f: f.write(password) 

to read the password from the file, try:

with open("password.txt","r") as f: password = f.read() 

Writing text (from a variable) into a file and on a new line in Python, txt file. This worked however it would always write to the same line, I was wondering how I would make the f.write(sumOfStudent) on a

Write string and variables to file in python

Turn it into one argument, such as with the newish format strings:

logfile.write(f'Total Matched lines : \n') 

Or, if you’re running a version before where this facility was added (3.6, I think), one of the following:

logfile.write('Total Matched lines : <>\n'.format(len(matched_lines))) logfile.write('Total Matched lines : ' + str(len(matched_lines)) + '\n') 

Aside: I’ve added a newline since you’re writing to a log file (most likely textual) and write does not do so. Feel free to ignore the \n if you’ve made the decision to not write it on an individual line.

logfile.write('Total Matched lines : <>'.format(len(matched_lines))) 

logfile.write('Total Matched lines : %d' % len(matched_lines)) 

logfile.write('Total matches lines: ' + str(len(matched_lines))) 

logfile.write('Total matches lines: <>'.format(len(matched_lines))) 

How to import variables from another file in Python?, We can use any Python source file as a module by executing an import statement in some swaps.py file from which variables to be imported.

Источник

Python write variable to file

File handling is an important concept of programming. Python allows us to read and write content to an external file.

In this article, we will discuss several ways to write variable to file in Python.

First, let us discuss the basics of file handling and how to write data to a file since this will be common with all the methods.

• To write data to an external file, we first open the required file using the open() function. This creates the file object associated with the required file.
• We need to open it in write mode, so it is necessary to specify the mode as w in the open() function.
• We can also add the type of the file using t and b while specifying the mode. Here, t indicates a text file, and b indicates a binary file.
• To write content to this file, we will use the write() function with the file object. We pass the contents as a string.
• After writing the necessary data, we can close the file using the close() function.
• We can avoid this close function by using the with statement to open the file. The with statement makes the code more readable, avoids exceptions, and removes the need to close the file.

A variable is a simple object which holds data in the memory and can be of any type. For our examples, we will use a dictionary and write this dictionary to a file. We will convert this dictionary to a string using different methods.

Using the str() function

The str() function is used to typecast a variable into a string. We can use this to convert the dictionary variable to a string and write it to a file.

Источник