1. Python
  2. f-strings in Python 3 — formatted string literals

f-strings in Python 3 — formatted string literals



To create an f-string, add a string with the letter “f”. The string itself can be formatted in much the same way as

# Python3 program representing the f-string

val = `Geeks`

print (f "{val} for {val} is a portal for {val}." )

 

 

name = `Tushar`

age = 23

print (f "Hello, My name is {name} and I`m {age} years old. " )

Output: 

 Hello, My name is Tushar and I`m 23 years old. Python.Engineering is a portal for Geeks.

Code # 2:

# Prints today`s date with
# time and date libraries

import datetime

  

today = datetime.datetime.today ()

print (f "{today:% B% d,% Y}" )

Output: 

 April 04, 2018

Note: F-strings are faster than the two most commonly used string formatting mechanisms: % formatting and str .format () .

Y Let`s take a look at a few examples of errors that can occur when using an f-line:

Code # 3: Demonstrate a syntax error.

answer = 456

f "Your answer is" {answer} ""

Code # 4: The backslash cannot be used directly in a format string.

f " newline: {ord (``)} "

Output: 

 Traceback (most recent call last): Python Shell, prompt 29, line 1 Syntax Error: f-string exp ression part cannot include a backslash:, line 1, pos 0

But the documentation indicates that we can put a backslash in a variable as a workaround:

newline = ord ( `` )

 

f "newline: {newline}"

Output: 

 newline: 10

Link: PEP 498, Literal String Interpolation