Lesson 4 of 10

Module 4 · Python for Beginners

Working with Text

Strings in depth: quotes and special characters, joining and repeating, length, indexing and slicing, the most useful string methods, splitting and joining, and f-string formatting.

About 30 minutes

Open in ColabEvery example as a notebook you can run, edit and save to your Google Drive.

Strings

Text in Python is a string (str): a sequence of characters in quotes. Single and double quotes work the same way:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Economics ECO 201

Use double quotes when the text contains an apostrophe, or single quotes when it contains double quotes:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

I'm in 200 level
She said "well done"

Special characters

A backslash \ starts a special character inside a string:

Write	Means
`\n`	a new line
`\t`	a tab
`\'` or `\"`	a quote inside quotes of the same kind
`\\`	one backslash

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Name:	Adaeze
Level:	300

For text over several lines, use triple quotes:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Block C, Room 14
Queen Amina Hall
University of Lagos

Joining and repeating

+ joins strings; * repeats one:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Chidi Okeke
--------------------

Length

len() counts the characters, including spaces:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Indexing: one character

Each character has a position, its index, starting at 0:

Character	P	y	t	h	o	n
Index	0	1	2	3	4	5
From the end	-6	-5	-4	-3	-2	-1

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

P
t
n

Negative indexes count from the end, so [-1] is always the last character, however long the string.

Slicing: part of a string

text[start:stop] takes the characters from start up to, but not including, stop:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

ECO
201
2026
ECO201
2026

Leave out start to begin at the start; leave out stop to go to the end.
The number of characters you get is stop − start: [0:3] gives 3.

String methods

A method is a function that belongs to a value. You call it with a dot: text.upper(). String methods never change the original string (strings can't be changed); they give you a new one.

Changing case

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

ADAEZE OKAFOR
adaeze okafor
Adaeze Okafor
Adaeze okafor

Removing spaces

Data typed by people often has stray spaces. strip() removes them from both ends:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

[   lagos  ]
[lagos]
[Lagos]

You can chain methods, as in the last line: strip, then title-case. lstrip() and rstrip() remove spaces from one side only.

Finding and replacing

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

musa.bello@unilag.edu.ng
10
2
True
True
True

find gives the index where something first appears, or -1 if it isn't there.
in asks "is this inside?" and gives True or False.

Checking what's in a string

Method	True when the string...	`"2026"`	`"ECO"`	`"ECO 201"`
`isdigit()`	is all digits	True	False	False
`isalpha()`	is all letters	False	True	False
`isupper()`	has no lowercase letters	False	True	True

These are useful for checking input before converting it, for example if text.isdigit(): number = int(text).

Splitting and joining

split() breaks a string into a list of pieces. With no argument, it splits on spaces:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

['Data', 'analysis', 'with', 'Python']
['Adaeze', 'Economics', '200', '4.21']

The second example is how a line of a CSV file breaks into its values. (Each piece is still text: "200", not 200.)

join() does the opposite: it glues a list of strings together, with the string you call it on between each piece:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

2026-09-15
Lagos, Abuja, Kano

f-strings in depth

An f-string puts values inside text. Anything in {} is worked out and inserted:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Musa owes ₦45,000
Half is 22500.0
In capitals: MUSA

After the value, a colon and a format control how it looks:

Format	Does	Example	Shows
`:,`	thousands separators	`{45000:,}`	`45,000`
`:.2f`	2 decimal places	`{3.14159:.2f}`	`3.14`
`:.0%`	as a percentage	`{0.25:.0%}`	`25%`
`:<10`	left-align in 10 spaces	`{"Food":<10}`	`Food`
`:>10`	right-align in 10 spaces	`{4500:>10}`	`4500`
`:^10`	centre in 10 spaces	`{"Hi":^10}`	`Hi`

Alignment lines up simple tables:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Item            Cost
Food          28,000
Data           6,000

When it goes wrong

word = "Python"
word[0] = "J"

Output

TypeError: 'str' object does not support item assignment

Strings can't be changed in place. Make a new one instead: word = "J" + word[1:].

print("Python"[10])

Output

IndexError: string index out of range

"Python" has positions 0 to 5. Slices don't raise this error ("Python"[3:10] gives "hon"), but single indexes do.

name = "musa"
name.upper()
print(name)

Output

musa

No error, but no change either: upper() returned a new string, and it was thrown away. Store it: name = name.upper().

Summary

You want to...	Write
join text	`first + " " + last`
count characters	`len(text)`
one character	`text[0]`, `text[-1]`
part of the text	`text[start:stop]`
change case	`.upper()`, `.lower()`, `.title()`
remove stray spaces	`.strip()`
replace	`.replace("old", "new")`
check if it contains	`"x" in text`
split into a list	`text.split(",")`
join a list	`", ".join(items)`
format a value	`f"{value:,.2f}"`

Try it

Practice

code = "ECO201-2026". What does code[3:6] give? Type it without quotes.

Practice

What does " abuja ".strip().title() give? Type it without quotes.

Practice

line = "Adaeze,Economics,200,4.21". How many items are in line.split(",")?

Task

10 min

Clean up a messy name and email: start with name = " aDAEZE okafor ". Print the name stripped and in title case, print its initials (first letter of each part, using split() and indexing), and build an email like adaeze.okafor@student.edu.ng from it in lowercase. Paste your code.

Your work is checked for

Uses strip()
Uses title()
Splits the name
Indexes a character with [0]
Makes it lowercase
Builds an email with @

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Take the module check

Questions on this module. Pass and you earn the Python Text badge, free.

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Lesson 4 of 10

Module 4 · Python for Beginners

Working with Text

Strings in depth: quotes and special characters, joining and repeating, length, indexing and slicing, the most useful string methods, splitting and joining, and f-string formatting.

About 30 minutes

Open in ColabEvery example as a notebook you can run, edit and save to your Google Drive.

Strings

Text in Python is a string (str): a sequence of characters in quotes. Single and double quotes work the same way:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Economics ECO 201

Use double quotes when the text contains an apostrophe, or single quotes when it contains double quotes:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

I'm in 200 level
She said "well done"

Special characters

A backslash \ starts a special character inside a string:

Write	Means
`\n`	a new line
`\t`	a tab
`\'` or `\"`	a quote inside quotes of the same kind
`\\`	one backslash

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Name:	Adaeze
Level:	300

For text over several lines, use triple quotes:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Block C, Room 14
Queen Amina Hall
University of Lagos

Joining and repeating

+ joins strings; * repeats one:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Chidi Okeke
--------------------

Length

len() counts the characters, including spaces:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Indexing: one character

Each character has a position, its index, starting at 0:

Character	P	y	t	h	o	n
Index	0	1	2	3	4	5
From the end	-6	-5	-4	-3	-2	-1

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

P
t
n

Negative indexes count from the end, so [-1] is always the last character, however long the string.

Slicing: part of a string

text[start:stop] takes the characters from start up to, but not including, stop:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

ECO
201
2026
ECO201
2026

Leave out start to begin at the start; leave out stop to go to the end.
The number of characters you get is stop − start: [0:3] gives 3.

String methods

A method is a function that belongs to a value. You call it with a dot: text.upper(). String methods never change the original string (strings can't be changed); they give you a new one.

Changing case

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

ADAEZE OKAFOR
adaeze okafor
Adaeze Okafor
Adaeze okafor

Removing spaces

Data typed by people often has stray spaces. strip() removes them from both ends:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

[   lagos  ]
[lagos]
[Lagos]

You can chain methods, as in the last line: strip, then title-case. lstrip() and rstrip() remove spaces from one side only.

Finding and replacing

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

musa.bello@unilag.edu.ng
10
2
True
True
True

find gives the index where something first appears, or -1 if it isn't there.
in asks "is this inside?" and gives True or False.

Checking what's in a string

Method	True when the string...	`"2026"`	`"ECO"`	`"ECO 201"`
`isdigit()`	is all digits	True	False	False
`isalpha()`	is all letters	False	True	False
`isupper()`	has no lowercase letters	False	True	True

These are useful for checking input before converting it, for example if text.isdigit(): number = int(text).

Splitting and joining

split() breaks a string into a list of pieces. With no argument, it splits on spaces:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

['Data', 'analysis', 'with', 'Python']
['Adaeze', 'Economics', '200', '4.21']

The second example is how a line of a CSV file breaks into its values. (Each piece is still text: "200", not 200.)

join() does the opposite: it glues a list of strings together, with the string you call it on between each piece:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

2026-09-15
Lagos, Abuja, Kano

f-strings in depth

An f-string puts values inside text. Anything in {} is worked out and inserted:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Musa owes ₦45,000
Half is 22500.0
In capitals: MUSA

After the value, a colon and a format control how it looks:

Format	Does	Example	Shows
`:,`	thousands separators	`{45000:,}`	`45,000`
`:.2f`	2 decimal places	`{3.14159:.2f}`	`3.14`
`:.0%`	as a percentage	`{0.25:.0%}`	`25%`
`:<10`	left-align in 10 spaces	`{"Food":<10}`	`Food`
`:>10`	right-align in 10 spaces	`{4500:>10}`	`4500`
`:^10`	centre in 10 spaces	`{"Hi":^10}`	`Hi`

Alignment lines up simple tables:

Python · try it yourself

Edit the code and press Run (Ctrl + Enter). Examples on this page share their variables, like cells in a notebook.

Output

Item            Cost
Food          28,000
Data           6,000

When it goes wrong

word = "Python"
word[0] = "J"

Output

TypeError: 'str' object does not support item assignment

Strings can't be changed in place. Make a new one instead: word = "J" + word[1:].

print("Python"[10])

Output

IndexError: string index out of range

"Python" has positions 0 to 5. Slices don't raise this error ("Python"[3:10] gives "hon"), but single indexes do.

name = "musa"
name.upper()
print(name)

Output

musa

No error, but no change either: upper() returned a new string, and it was thrown away. Store it: name = name.upper().

Summary

You want to...	Write
join text	`first + " " + last`
count characters	`len(text)`
one character	`text[0]`, `text[-1]`
part of the text	`text[start:stop]`
change case	`.upper()`, `.lower()`, `.title()`
remove stray spaces	`.strip()`
replace	`.replace("old", "new")`
check if it contains	`"x" in text`
split into a list	`text.split(",")`
join a list	`", ".join(items)`
format a value	`f"{value:,.2f}"`

Try it

Practice

code = "ECO201-2026". What does code[3:6] give? Type it without quotes.

Practice

What does " abuja ".strip().title() give? Type it without quotes.

Practice

line = "Adaeze,Economics,200,4.21". How many items are in line.split(",")?

Task

10 min

Your work is checked for

Uses strip()
Uses title()
Splits the name
Indexes a character with [0]
Makes it lowercase
Builds an email with @

Earn your badge

Take the module check

Questions on this module. Pass and you earn the Python Text badge, free.

Create a free account to earn the badge