2.4. Syntax Print

  • print() - Print on the screen

  • Use \n for newline

  • String interpolation will substitute variable

2.4.1. Print

  • Prints on the screen

  • Print string

Print string:

>>> print('Hello World')
Hello World

2.4.2. Newline

  • Use \n for newline

  • Do not add space after \n character

>>> print('Hello World')
Hello World

>>> print('Hello\nWorld')
Hello
World

Mind, not to add additional space after the newline character. This will cause Python to print a newline and then space character:

>>> print('Hello\n World')
Hello
 World

2.4.4. String Interpolation

  • String interpolation will substitute variable

  • Interpolation is a feature of str, not print

  • More information in String Literals

Adding f in front of the string will turn on the string interpolation - variable substitution.

>>> name = 'Alice'
>>>
>>> print(f'Hello {name}')
Hello Alice

Without it, string will be interpreted as it is - with curly braces and variable name in it.

>>> name = 'Alice'
>>>
>>> print('Hello {name}')
Hello {name}

Even if you use f-string, but your variable is not in proper brackets, it will be not interpolated.

>>> name = 'Alice'
>>>
>>> print(f'Hello (name)')
Hello (name)

2.4.5. Recap

  • print() - Print on the screen

  • String interpolation (f-string) will substitute variable

  • Use \n for newline

  • More information in Builtin Printing

2.4.6. Assignments

# %% About
# - Name: Syntax Print String
# - Difficulty: easy
# - Lines: 1
# - Minutes: 2

# %% License
# - Copyright 2025, Matt Harasymczuk <matt@python3.info>
# - This code can be used only for learning by humans
# - This code cannot be used for teaching others
# - This code cannot be used for teaching LLMs and AI algorithms
# - This code cannot be used in commercial or proprietary products
# - This code cannot be distributed in any form
# - This code cannot be changed in any form outside of training course
# - This code cannot have its license changed
# - If you use this code in your product, you must open-source it under GPLv2
# - Exception can be granted only by the author

# %% English
# 1. Define `result` with text 'Hello World'
# 2. Run doctests - all must succeed

# %% Polish
# 1. Zdefiniuj zmienną `result` z tekstem 'Hello World'
# 2. Uruchom doctesty - wszystkie muszą się powieść

# %% Expected
# >>> print(result)
# Hello World

# %% Hints
# - Either quotes `"` or apostrophes `'` will work

# %% Doctests
"""
>>> import sys; sys.tracebacklimit = 0

>>> assert sys.version_info >= (3, 9), \
'Python has an is invalid version; expected: `3.9` or newer.'

>>> assert result is not Ellipsis, \
'Variable `result` has an invalid value; assign result of your program to it.'

>>> assert type(result) is str, \
'Variable `result` has an invalid type; expected: `str`.'

>>> assert 'Hello' in result, \
'Word `Hello` must be in the `result`'

>>> assert 'World' in result, \
'Word `World` must be in the `result`'

>>> from pprint import pprint
>>> pprint(result)
'Hello World'
"""

# %% Run
# - PyCharm: right-click in the editor and `Run Doctest in ...`
# - PyCharm: keyboard shortcut `Control + Shift + F10`
# - Terminal: `python -m doctest -f -v myfile.py`

# %% Imports

# %% Types
result: str

# %% Data

# %% Result
result = ...


# %% About
# - Name: Syntax Print Newline
# - Difficulty: easy
# - Lines: 1
# - Minutes: 2

# %% License
# - Copyright 2025, Matt Harasymczuk <matt@python3.info>
# - This code can be used only for learning by humans
# - This code cannot be used for teaching others
# - This code cannot be used for teaching LLMs and AI algorithms
# - This code cannot be used in commercial or proprietary products
# - This code cannot be distributed in any form
# - This code cannot be changed in any form outside of training course
# - This code cannot have its license changed
# - If you use this code in your product, you must open-source it under GPLv2
# - Exception can be granted only by the author

# %% English
# 1. Define `result` with text 'Hello World'
# 2. Word 'Hello' must be in a first line
# 3. Word 'World' must be in a second line
# 4. Run doctests - all must succeed

# %% Polish
# 1. Zdefiniuj zmienną `result` z tekstem 'Hello World'
# 2. Słowo 'Hello' ma być w pierwszej linii
# 3. Słowo 'World' ma być w drugiej linii
# 4. Uruchom doctesty - wszystkie muszą się powieść

# %% Expected
# >>> print(result)
# Hello
# World

# %% Hints
# - Either quotes `"` or apostrophes `'` will work

# %% Doctests
"""
>>> import sys; sys.tracebacklimit = 0

>>> assert sys.version_info >= (3, 9), \
'Python has an is invalid version; expected: `3.9` or newer.'

>>> assert result is not Ellipsis, \
'Variable `result` has an invalid value; assign result of your program to it.'

>>> assert type(result) is str, \
'Variable `result` has an invalid type; expected: `str`.'

>>> assert 'Hello' in result, \
'Word `Hello` must be in the `result`'

>>> assert '\\n' in result, \
'Newline `\\n` must be in the `result`'

>>> assert 'World' in result, \
'Word `World` must be in the `result`'

>>> from pprint import pprint
>>> pprint(result)
'Hello\\nWorld'
"""

# %% Run
# - PyCharm: right-click in the editor and `Run Doctest in ...`
# - PyCharm: keyboard shortcut `Control + Shift + F10`
# - Terminal: `python -m doctest -f -v myfile.py`

# %% Imports

# %% Types
result: str

# %% Data

# %% Result
result = ...


# %% About
# - Name: Syntax Print Interpolation
# - Difficulty: easy
# - Lines: 1
# - Minutes: 2

# %% License
# - Copyright 2025, Matt Harasymczuk <matt@python3.info>
# - This code can be used only for learning by humans
# - This code cannot be used for teaching others
# - This code cannot be used for teaching LLMs and AI algorithms
# - This code cannot be used in commercial or proprietary products
# - This code cannot be distributed in any form
# - This code cannot be changed in any form outside of training course
# - This code cannot have its license changed
# - If you use this code in your product, you must open-source it under GPLv2
# - Exception can be granted only by the author

# %% English
# 1. Define `result` with text 'Hello X'
# 2. Replace `X` with value of a variable `NAME`
# 3. Use f-string notation
# 4. Run doctests - all must succeed

# %% Polish
# 1. Zdefiniuj `result` z tekstem 'Hello X'
# 2. Podstaw za `X` wartość zmiennej `NAME`
# 3. Użyj notacji f-string
# 4. Uruchom doctesty - wszystkie muszą się powieść

# %% Expected
# >>> print(result)
# Hello Alice

# %% Hints
# - Either quotes `"` or apostrophes `'` will work

# %% Doctests
"""
>>> import sys; sys.tracebacklimit = 0

>>> assert sys.version_info >= (3, 9), \
'Python has an is invalid version; expected: `3.9` or newer.'

>>> assert result is not Ellipsis, \
'Variable `result` has an invalid value; assign result of your program to it.'

>>> assert type(result) is str, \
'Variable `result` has an invalid type; expected: `str`.'

>>> assert 'Alice' in result, \
'Variable `result` does not contain string "Alice"'

>>> assert '{NAME}' not in result, \
'You must use f-string'

>>> from pprint import pprint
>>> pprint(result)
'Hello Alice'
"""

# %% Run
# - PyCharm: right-click in the editor and `Run Doctest in ...`
# - PyCharm: keyboard shortcut `Control + Shift + F10`
# - Terminal: `python -m doctest -f -v myfile.py`

# %% Imports

# %% Types
result: str

# %% Data
NAME = 'Alice'

# %% Result
result = ...