The print() function in Python is used to output text or other data to the console or standard output. It can print strings, numbers, variables, and more, and supports multiple arguments and formatting.
print("Hello, world!")
# Output: Hello, world!
You can pass multiple arguments to the print() function. The arguments are separated by commas.
print("The answer is", 42)
# Output: The answer is 42
The print() function in Python has two optional parameters, sep and end, that can be used to customize the output of the function.
print("apple", "banana", "cherry", sep=", ")
# Output: apple, banana, cherry
print("Hello", end=" ")
print("world!")
# Output: Hello world!
name = "Alice"
age = 30
print("Name:", name)
print("Age:", age)
# Output:
# Name: Alice
# Age: 30
Python 3.6 introduced f-strings, which provide a concise and convenient way to embed expressions inside string literals, using curly braces {}. They are prefixed with the letter f or F and are evaluated at runtime.
name = "Alice"
age = 30
print(f"My name is {name} and I am {age} years old.")
# Output: My name is Alice and I am 30 years old.
str.format()str.format() is a built-in method that allows multiple substitutions and value formatting. This method lets us concatenate elements within a string through positional formatting.
name = "Alice"
age = 30
print("My name is {} and I am {} years old.".format(name, age))
# Output: My name is Alice and I am 30 years old.
This is an older method of formatting strings in Python. It uses the % operator to format a set of variables enclosed in a tuple (fixed-size array). The format string contains one or more format codes, which specify how the values should be formatted.
name = "Alice"
age = 30
print("My name is %s and I am %d years old." % (name, age))
# Output: My name is Alice and I am 30 years old.
fruits = ["apple", "banana", "cherry"]
print(fruits)
# Output: ['apple', 'banana', 'cherry']
The file parameter in the print() function is used to specify the file to write the output to. By default, the output is printed to the console.
# Redirecting print output to a file
with open("output.txt", "w") as file:
print("Hello, world!", file=file)
# This writes "Hello, world!" to the file "output.txt"
The flush parameter in the print() function is used to forcibly flush the stream. By default, the stream is not flushed.
import time
for i in range(5):
print(i, end=" ", flush=True)
time.sleep(1)
# Output: 0 1 2 3 4 (printed with a delay of 1 second between each number)