Python String Operations With Examples

Python String operations

capitalize() Converts the first character to upper case

>>> txt = "hello, and welcome to my world."

>>> y=txt.capitalize()

>>> print(y)

Hello, and welcome to my world.

casefold() Converts string into lower case

>>> txt = "Hello, And Welcome To My World!"

>>> x = txt.casefold()

>>> print(x)

hello, and welcome to my world!

center() Returns a centered string

>>> txt = "banana"

>>> x = txt.center(20)

>>> print(x)

       banana

>>> txt = "banana"

>>> x = txt.center(20, "O")

>>> print(x)

OOOOOOObananaOOOOOOO

count() Returns the number of times a specified value occurs in a string

>>> txt = "I love apples, apple are my favorite fruit"

>>> x = txt.count("apple")

>>> print(x)

2

>>> txt = "I love apples, apple are my favorite fruit"

>>> x = txt.count("apple", 10, 24)

>>> print(x)

1

encode() Returns an encoded version of the string

>>> txt = "My name is Ståle"

>>> x = txt.encode()

>>> print()

>>> print(x)

b'My name is St\xc3\xa5le'

endswith() Returns true if the string ends with the specified value

>>> txt = "Hello, welcome to my world."

>>> x = txt.endswith("my world.")

>>> print(x)

True

>>> txt = "Hello, welcome to my world."

>>> x = txt.endswith("my world.", 5, 11)

>>> print(x)

False

expandtabs() Sets the tab size of the string

>>> txt = "H\te\tl\tl\to"

>>> print(txt)

H       e       l       l       o

>>> print(txt.expandtabs())

H       e       l       l       o

>>> print(txt.expandtabs(2))

H e l l o

>>> print(txt.expandtabs(4))

H   e   l   l   o

>>> print(txt.expandtabs(10))

H         e         l         l         o

find() Searches the string for a specified value and returns the position of where it was found

>>> x = txt.find("welcome")

>>> print(x)

7

>>> txt = "Hello, welcome to my world."

>>> x = txt.find("e")

>>> print(x)

1

>>> txt = "Hello, welcome to my world."

>>> print(txt.find("q"))

-1

>>> print(txt.index("q"))

Traceback (most recent call last):

  File "", line 1, in

ValueError: substring not found

index() Searches the string for a specified value and returns the position of where it was found

>>> txt = "Hello, welcome to my world."

>>> x = txt.index("welcome")

>>> print(x)

7

>>> txt = "Hello, welcome to my world."

>>> print(txt.find("q"))

-1

>>> print(txt.index("q"))

Traceback (most recent call last):

  File "", line 1, in

ValueError: substring not found

isalnum() Returns True if all characters in the string are alphanumeric

>>> txt = "Company12"

>>> x = txt.isalnum()

>>> print(x)

True

>>> txt = "Company 12"

>>> x = txt.isalnum()

>>> print(x)

False

isalpha() Returns True if all characters in the string are in the alphabet

>>> txt = "CompanyX"

>>> x = txt.isalpha()

>>> print(x)

True

>>> txt = "Company10"

>>> x = txt.isalpha()

>>> print(x)

False

isdecimal() Returns True if all characters in the string are decimals

>>> txt = "\u0033" #unicode for 3

>>> x = txt.isdecimal()

>>> print(x)

True

>>> a = "\u0030" #unicode for 0

>>> b = "\u0047" #unicode for G

>>> print(a.isdecimal())

True

>>> print(b.isdecimal())

False

isdigit() Returns True if all characters in the string are digits

>>> txt = "50800"

>>> x = txt.isdigit()

>>> print(x)

True

>>> a = "\u0030" #unicode for 0

>>> b = "\u00B2" #unicode for ²

>>> print(a.isdigit())

True

>>> print(b.isdigit())

True

isidentifier() Returns True if the string is an identifier

>>> txt = "Demo"

>>> x = txt.isidentifier()

>>> print(x)

True

>>> a = "MyFolder"

>>> b = "Demo002"

>>> c = "2bring"

>>> d = "my demo"

>>> print(a.isidentifier())

True

>>> print(b.isidentifier())

True

>>> print(c.isidentifier())

False

>>> print(d.isidentifier())

False

islower() Returns True if all characters in the string are lower case

>>> txt = "hello world!"

>>> x = txt.islower()

>>> print(x)

True

>>> a = "Hello world!"

>>> b = "hello 123"

>>> c = "mynameisPeter"

>>> print(a.islower())

False

>>> print(b.islower())

True

>>> print(c.islower())

False

isnumeric() Returns True if all characters in the string are numeric

>>> txt = "565543"

>>> x = txt.isnumeric()

>>> print(x)

True

>>> a = "\u0030" #unicode for 0

>>> b = "\u00B2" #unicode for ²

>>> c = "10km2"

>>> print(a.isnumeric())

True

>>> print(b.isnumeric())

True

>>> print(c.isnumeric())

False

isprintable() Returns True if all characters in the string are printable

txt = "Hello! Are you #1?"

>>> x = txt.isprintable()

>>> print(x)

True

>>> txt = "Hello!\nAre you #1?"

>>> x = txt.isprintable()

>>> print(x)

False

isspace() Returns True if all characters in the string are whitespaces

>>> txt = "   "

>>> x = txt.isspace()

>>> 

>>> print(x)

True

>>> txt = "   s   "

>>> x = txt.isspace()

>>> print(x)

False

istitle() Returns True if the string follows the rules of a title

>>> txt = "Hello, And Welcome To My World!"

>>> x = txt.istitle()

>>> print(x)

True

>>> a = "HELLO, AND WELCOME TO MY WORLD"

>>> b = "Hello"

>>> c = "22 Names"

>>> d = "This Is %'!?"

>>> print(a.istitle())

False

>>> print(b.istitle())

True

>>> print(c.istitle())

True

>>> print(d.istitle())

True

isupper() Returns True if all characters in the string are upper case

>>> txt = "THIS IS NOW!"

>>> x = txt.isupper()

>>> print(x)

True

>>> a = "Hello World!"

>>> b = "hello 123"

>>> c = "MY NAME IS PETER"

>>> print(a.isupper())

False

>>> print(b.isupper())

False

>>> print(c.isupper())

True

join() Joins the elements of an iterable to the end of the string

>>> myTuple = ("John", "Peter", "Vicky")

>> x = "#".join(myTuple)

>>> print(x)

John#Peter#Vicky

>>> myDict = {"name": "John", "country": "Norway"}

>>> mySeparator = "TEST"

>>> x = mySeparator.join(myDict)

>>> print(x)

nameTESTcountry

ljust() Returns a left justified version of the string

>>> txt = "banana"

>>> x = txt.ljust(20)

>>> print(x, "is my favorite fruit.")

banana               is my favorite fruit.

>>> txt = "banana"

>>> x = txt.ljust(20, "O")

>>> print(x)

bananaOOOOOOOOOOOOOO

lower() Converts a string into lower case

>>> txt = "Hello my FRIENDS"

>>> x = txt.lower()

>>> print(x)

hello my friends

lstrip() Returns a left trim version of the string

>>> txt = "     banana     "

>>> x = txt.lstrip()

>>> print("of all fruits", x, "is my favorite")

of all fruits banana      is my favorite

>>> txt = ",,,,,ssaaww.....banana"

>>> x = txt.lstrip(",.asw")

>>> print(x)

Banana

partition() Returns a tuple where the string is parted into three parts

>>> txt = "I could eat bananas all day"

>>> x = txt.partition("bananas")

>>> print(x)

('I could eat ', 'bananas', ' all day')

>>> txt = "I could eat bananas all day"

>>> x = txt.partition("apples")

>>> print(x)

('I could eat bananas all day', '', '')

replace() Returns a string where a specified value is replaced with a specified value

I could eat apples all day

>>> txt = "one one was a race horse, two two was one too."

>>> x = txt.replace("one", "three")

>>> print(x)

three three was a race horse, two two was three too.

>>> txt = "one one was a race horse, two two was one too."

>>> x = txt.replace("one", "three", 2)

>>> print(x)

three three was a race horse, two two was one too.

rfind() Searches the string for a specified value and returns the last position of where it was found

>>> txt = "Mi casa, su casa."

>>> x = txt.rfind("casa")

>>> print(x)

12

>>> txt = "Hello, welcome to my world."

>>> x = txt.rfind("e")

>>> print(x)

13

>>> txt = "Hello, welcome to my world."

>>> x = txt.rfind("e", 5, 10)

>>> print(x)

8

>>> txt = "Hello, welcome to my world."

>>> print(txt.rfind("q"))

-1

>>> print(txt.rindex("q"))

Traceback (most recent call last):

  File "", line 1, in

ValueError: substring not found

>>> 

rindex()Searches the string for a specified value and returns the last position of where it was found

>>> txt = "Mi casa, su casa."

>>> x = txt.rindex("casa")

>>> print(x)

12

>>> txt = "Hello, welcome to my world."

>>> x = txt.rindex("e")

>>> print(x)

13

>>> txt = "Hello, welcome to my world."

>>> x = txt.rindex("e", 5, 10)

>>> print(x)

8

>>> txt = "Hello, welcome to my world."

>>> print(txt.rfind("q"))

-1

>>> print(txt.rindex("q"))

Traceback (most recent call last):

  File "", line 1, in

ValueError: substring not found

rjust() Returns a right justified version of the string

>>> txt = "banana"

>>> x = txt.rjust(20)

>>> print(x, "is my favorite fruit.")

              banana is my favorite fruit.

>>> txt = "banana"

>>> x = txt.rjust(20, "O")

>>> print(x)

OOOOOOOOOOOOOObanana

rpartition() Returns a tuple where the string is parted into three parts

>>> txt = "I could eat bananas all day, bananas are my favorite fruit"

>>> x = txt.rpartition("bananas")

>>> print(x)

('I could eat bananas all day, ', 'bananas', ' are my favorite fruit')

>>> txt = "I could eat bananas all day, bananas are my favorite fruit"

>>> x = txt.rpartition("apples")

>>> print(x)

('', '', 'I could eat bananas all day, bananas are my favorite fruit')

rsplit() Splits the string at the specified separator, and returns a list

>>> txt = "apple, banana, cherry"

>>> x = txt.rsplit(", ")

>>> print(x)

['apple', 'banana', 'cherry']

>>> txt = "apple, banana, cherry"

>>> # setting the max parameter to 1, will return a list with 2 elements!

... x = txt.rsplit(", ", 1)

>>> print(x)

['apple, banana', 'cherry']

rstrip() Returns a right trim version of the string

>>> txt = "     banana     "

>>> x = txt.rstrip()

>>> print("of all fruits", x, "is my favorite")

of all fruits      banana is my favorite

>>> txt = "banana,,,,,ssaaww....."

>>> x = txt.rstrip(",.asw")

>>> print(x)

Banan

split() Splits the string at the specified separator, and returns a list

>>> txt = "welcome to the jungle"

>>> x = txt.split()

>>> print(x)

['welcome', 'to', 'the', 'jungle']

>>> txt = "hello, my name is Peter, I am 26 years old"

>>> x = txt.split(", ")

>>> print(x)

['hello', 'my name is Peter', 'I am 26 years old']

>>> txt = "apple#banana#cherry#orange"

>>> x = txt.split("#")

>>> print(x)

['apple', 'banana', 'cherry', 'orange']

>>> txt = "apple#banana#cherry#orange"

>>> # setting the max parameter to 1, will return a list with 2 elements!

... x = txt.split("#", 1)

>>> print(x)

['apple', 'banana#cherry#orange']

splitlines() Splits the string at line breaks and returns a list

>>> txt = "Thank you for the music\nWelcome to the jungle"

>>> x = txt.splitlines()

>>> print(x)

['Thank you for the music', 'Welcome to the jungle']

>>> txt = "Thank you for the music\nWelcome to the jungle"

>>> x = txt.splitlines(True)

>>> print(x)

['Thank you for the music\n', 'Welcome to the jungle']

startswith() Returns true if the string starts with the specified value

>>> txt = "Hello, welcome to my world."

>>> x = txt.startswith("Hello")

>>> print(x)

True

>>> txt = "Hello, welcome to my world."

>>> x = txt.startswith("wel", 7, 20)

strip() Returns a trimmed version of the string

>>> txt = "     banana     "

>>> x = txt.strip()

>>> print("of all fruits", x, "is my favorite")

of all fruits banana is my favorite

>>> txt = ",,,,,rrttgg.....banana....rrr"

>>> x = txt.strip(",.grt")

>>> print(x)

Banana

swapcase() Swaps cases, lower case becomes upper case and vice versa

>>> txt = "Hello My Name Is PETER"

>>> x = txt.swapcase()

>>> print(x)

hELLO mY nAME iS peter

title() Converts the first character of each word to upper case

>>> txt = "Welcome to my world"

>>> x = txt.title()

>>> print(x)

Welcome To My World

>>> txt = "Welcome to my 2nd world"

>>> x = txt.title()

>>> print(x)

Welcome To My 2Nd World

>>> txt = "hello b2b2b2 and 3g3g3g"

>>> x = txt.title()

>>> print(x)

Hello B2B2B2 And 3G3G3G

upper() Converts a string into upper case

>>> txt = "Hello my friends"

>>> x = txt.upper()

>>> print(x)

HELLO MY FRIENDS

zfill() Fills the string with a specified number of 0 values at the beginning+

>>> txt = "50"

>>> x = txt.zfill(10)

>>> print(x)

0000000050

>>> a = "hello"

>>> b = "welcome to the jungle"

>>> c = "10.000"

>>> print(a.zfill(10))

00000hello

>>> print(b.zfill(10))

welcome to the jungle

>>> print(c.zfill(10))

000010.000