I'm using Python to open a text document:
text_file = open("Output.txt", "w")
text_file.write("Purchase Amount: " 'TotalAmount')
text_file.close()
I want to substitute the value of a string variable TotalAmount into the text document. Can someone please let me know how to do this?
7 Answers
It is strongly advised to use a context manager. As an advantage, it is made sure the file is always closed, no matter what:
with open("Output.txt", "w") as text_file:
text_file.write("Purchase Amount: %s" % TotalAmount)
This is the explicit version (but always remember, the context manager version from above should be preferred):
text_file = open("Output.txt", "w")
text_file.write("Purchase Amount: %s" % TotalAmount)
text_file.close()
If you're using Python2.6 or higher, it's preferred to use str.format()
with open("Output.txt", "w") as text_file:
text_file.write("Purchase Amount: {0}".format(TotalAmount))
For python2.7 and higher you can use {} instead of {0}
In Python3, there is an optional file parameter to the print function
with open("Output.txt", "w") as text_file:
print("Purchase Amount: {}".format(TotalAmount), file=text_file)
Python3.6 introduced f-strings for another alternative
with open("Output.txt", "w") as text_file:
print(f"Purchase Amount: {TotalAmount}", file=text_file)
In case you want to pass multiple arguments you can use a tuple
price = 33.3
with open("Output.txt", "w") as text_file:
text_file.write("Purchase Amount: %s price %f" % (TotalAmount, price))
If you are using Python3.
then you can use Print Function :
your_data = {"Purchase Amount": 'TotalAmount'}
print(your_data, file=open('D:\log.txt', 'w'))
For python2
this is the example of Python Print String To Text File
def my_func():
"""
this function return some value
:return:
"""
return 25.256
def write_file(data):
"""
this function write data to file
:param data:
:return:
"""
file_name = r'D:\log.txt'
with open(file_name, 'w') as x_file:
x_file.write('{} TotalAmount'.format(data))
def run():
data = my_func()
write_file(data)
run()
With using pathlib module, indentation isn't needed.
import pathlib
pathlib.Path("output.txt").write_text("Purchase Amount: {}" .format(TotalAmount))
As of python 3.6, f-strings is available.
pathlib.Path("output.txt").write_text(f"Purchase Amount: {TotalAmount}")
If you are using numpy, printing a single (or multiply) strings to a file can be done with just one line:
numpy.savetxt('Output.txt', ["Purchase Amount: %s" % TotalAmount], fmt='%s')
use of f-string is a good option because we can put multiple parameters with syntax like str,
for example:
import datetime
now = datetime.datetime.now()
price = 1200
currency = "INR"
with open("D:\\log.txt","a") as f:
f.write(f'Product sold at {currency} {price } on {str(now)}\n')
If you need to split a long HTML string in smaller strings and add them to a .txt file separated by a new line \n use the python3 script below.
In my case I am sending a very long HTML string from server to client and I need to send small strings one after another.
Also be careful with UnicodeError if you have special characters like for example the horizontal bar ― or emojis, you will need to replace them with others chars beforehand.
Also make sure you replace the "" inside your html with ''
#decide the character number for every division
divideEvery = 100
myHtmlString = "<!DOCTYPE html><html lang='en'><title>W3.CSS Template</title><meta charset='UTF-8'><meta name='viewport' content='width=device-width, initial-scale=1'><link rel='stylesheet' href=' rel='stylesheet' href=' rel='stylesheet' href=' {font-family: 'Lato', sans-serif}.mySlides {display: none}</style><body></body></html>"
myLength = len(myHtmlString)
division = myLength/divideEvery
print("number of divisions")
print(division)
carry = myLength%divideEvery
print("characters in the last piece of string")
print(carry)
f = open("result.txt","w+")
f.write("Below the string splitted \r\n")
f.close()
x=myHtmlString
n=divideEvery
myArray=[]
for i in range(0,len(x),n):
myArray.append(x[i:i+n])
#print(myArray)
for item in myArray:
f = open('result.txt', 'a')
f.write('server.sendContent(\"'+item+'\");' '\n'+ '\n')
f.close()
