print() function basics in Python - Step-by-Step Execution

Concept Flow - print() function basics

Start

↓

Call print()

↓

Evaluate arguments

↓

Convert to string

↓

Send to output (screen)

↓

End

The print() function takes inputs, converts them to text, and shows them on the screen.

Execution Sample

Python

print("Hello, world!")

This code prints the text Hello, world! on the screen.

Execution Table

Step	Action	Input	Output
1	Call print()	"Hello, world!"	Prepare to print
2	Evaluate argument	"Hello, world!"	"Hello, world!" as string
3	Send to output	"Hello, world!"	Hello, world! displayed on screen
4	End	-	-

💡 print() finishes after showing the text on the screen

Variable Tracker

Variable	Start	After print() call	Final
argument	None	None	None (print does not store)

Key Moments - 2 Insights

Why does print() show text but not store it in a variable?

print() only sends text to the screen; it does not save or return any value. See execution_table step 3 where output is displayed but no variable changes.

What happens if we print a number instead of text?

The number is converted to text before printing, just like the string. This is shown in execution_table step 2 where input is converted to string.

Visual Quiz - 3 Questions

Look at the execution table, what is the output at step 3?

A The text is displayed on the screen

B The text is stored in a variable

C The program stops running

D Nothing happens

💡 Hint

Check the Output column at step 3 in the execution_table

According to the variable tracker, what happens to the argument variable after print() is called?

A It keeps the printed text

B It becomes None

C It is deleted

D It changes to a number

💡 Hint

Look at the 'After print() call' column for 'argument' in variable_tracker

If we change print("Hello") to print(123), what changes in the execution flow?

A The output will be a number type on screen

B print() will not work with numbers

C The argument is converted to string before printing

D The program will crash

💡 Hint

Refer to concept_flow and execution_table step 2 about argument evaluation

Concept Snapshot

print() function basics:
- Use print() to show text or values on screen
- Arguments are converted to strings automatically
- print() does not save or return values
- Syntax: print(value1, value2, ...)
- Each call outputs on a new line by default

Full Transcript

The print() function in Python is used to show messages or values on the screen. When you call print(), it takes the input you give it, changes it into text if needed, and then shows it on the screen. It does not save the text anywhere or return any value. For example, print("Hello, world!") will display Hello, world! on the screen. The process starts by calling print(), then the input is evaluated and converted to a string, and finally the text is sent to the output. After printing, the program continues or ends. Variables passed to print() do not change or store the printed text. This is important to understand so you know print() is only for showing information, not for storing it.

Practice

1. What does the print() function do in Python?

easy

A. It displays messages or values on the screen.

B. It saves data to a file.

C. It reads input from the user.

D. It creates a new variable.

Solution

1. Step 1: Understand the purpose of print()

   The print() function is used to show messages or values on the screen, making it easy to see output from the program.

2. Step 2: Compare with other options

   Saving data, reading input, or creating variables are done by other functions, not print().

3. Final Answer:

   It displays messages or values on the screen. -> Option A

4. Quick Check:

   print() shows output [OK]

Hint: Remember: print() means show on screen [OK]

Common Mistakes:

• Confusing print() with input()
• Thinking print() saves data
• Assuming print() creates variables

2. Which of the following is the correct way to print the words Hello and World separated by a space?

easy

A. print('Hello' 'World')

B. print('Hello' + 'World')

C. print('Hello', 'World')

D. print('Hello'; 'World')

Solution

1. Step 1: Understand how print separates items

   Using commas in print() separates items with spaces by default, so print('Hello', 'World') prints "Hello World".

2. Step 2: Check other options

   print('Hello' 'World') joins strings without space; print('Hello' + 'World') concatenates without space; print('Hello'; 'World') uses invalid syntax.

3. Final Answer:

   print('Hello', 'World') -> Option C

4. Quick Check:

   Comma adds space in print() [OK]

Hint: Use commas to print multiple items with spaces [OK]

Common Mistakes:

• Forgetting commas between items
• Using semicolon inside print()
• Concatenating without spaces

3. What will be the output of this code?

print('A', 'B', 'C', sep='-')

medium

A. A B C

B. A-B-C

C. ABC

D. A-B C

Solution

1. Step 1: Understand the sep parameter in print()

   The sep parameter changes the separator between printed items. Here, it is set to '-'.

2. Step 2: Apply sep to the items

   Items 'A', 'B', 'C' will be joined with '-' between them, resulting in 'A-B-C'.

3. Final Answer:

   A-B-C -> Option B

4. Quick Check:

   sep='-' joins items with dash [OK]

Hint: sep changes space to your chosen separator [OK]

Common Mistakes:

• Ignoring sep and expecting spaces
• Confusing sep with end
• Missing quotes around separator

4. The code below gives an error. What is the problem?

print('Hello' end='!')

medium

A. Missing comma between arguments

B. end parameter cannot be used

C. Quotes are incorrect

D. print() cannot print strings

Solution

1. Step 1: Check syntax of print() arguments

   Arguments in print() must be separated by commas. Here, 'Hello' and end='!' are missing a comma.

2. Step 2: Understand correct usage

   Correct syntax is print('Hello', end='!') with a comma separating the string and the keyword argument.

3. Final Answer:

   Missing comma between arguments -> Option A

4. Quick Check:

   Separate print args with commas [OK]

Hint: Separate print arguments with commas [OK]

Common Mistakes:

• Forgetting commas between arguments
• Thinking end is not allowed
• Misplacing quotes

5. How can you print the numbers 1, 2, and 3 on the same line separated by commas, but end the line with a period instead of a newline?

hard

A. print(1, 2, 3, sep=',') print(end='.')

B. print(1, 2, 3, sep='.', end=',')

C. print(1, 2, 3, sep=', end='.')

D. print(1, 2, 3, sep=',', end='.')

Solution

1. Step 1: Use sep to set commas between numbers

   Setting sep=',' prints numbers separated by commas: '1,2,3'.

2. Step 2: Use end to replace newline with a period

   Setting end='.' prints a period instead of moving to a new line.

3. Step 3: Check argument order

   Argument order does not matter, but both sep and end must be included in the same print call.

4. Final Answer:

   print(1, 2, 3, sep=',', end='.') -> Option D

5. Quick Check:

   sep=',' and end='.' print 1,2,3. [OK]

Hint: Use sep for commas and end for period [OK]

Common Mistakes:

• Swapping sep and end values
• Using two print statements instead of one
• Forgetting to set end to '.'