Functions: String functions in python:

Format() function :

>>>name = “Alexander”

>>>car_color = “red.”

>>>print(“hello world, my name is”+ “ ”+name+“ ”+“,and my car color is”

+ “ “+car_color)

hello world, my name is Alexander ,and my car color is red

msg = “hello world, my name is {} , and my car color is {}.format(name, car_color)

>>> print(msg)

hello world, my name is Alexander ,and my car color is red.



String len() function:

>>> print(len(msg))

58

>>> print(len(name))

9

>>> print(len(name[0:4]))

4

>>> Print(Name[0:4])

Alex


Used to count the entire string or specific character of a string

>>>‘This is user car’.count(‘r’)

2

In order to count from index 5 to end of string

>>>‘This is user car’.count(‘r’, 5)

2

In order to count from index 5 to 12
>>> ‘This is user car(‘s’, 5, 12 )

1


In orde count ‘T’. There’s only 1 ‘T’ as the function is case sensitive:

Example:


>>>‘This is user car’.count(‘T’)

1

>>>‘This is user car’.count(‘u’)

1

>>>‘This is user car’.count(‘U’)

0




endswith () and startswith() functions:

this function Return True if the string ends with the specified suffix, otherwise return False and it is case-sensitive function.

Example:

In order to check if a string contain specific suffix like car

>>>‘user_car’.endswith(‘car’)

True

# check from index 4 to end of string

>>>‘‘user_car’.endswith(‘car’, 4)

True




To check from index 5 to 7

>>>‘user_car’.endswith(‘car’, 5, 7)

False

To check from index 4 to 8

>>>‘‘user_car’.endswith(‘car’,4, 8)

True

In order to use a tuple of suffixes as we check from index 4 to 8

>>>‘‘user_car’.endswith((‘car’, ‘ar’), 4, 8)

True

Startswith() like endwiths() but used for bega



Find() string function:

Return the index in the string where the first occurrence of the substring sub is found

Examples:

In order to check specific character in a string

>>>‘This is user_car’.find(‘i’)

2

In order to check from index 2 to end of a string

>>>‘This is user_car’.find(‘s’, 2)

3



In order to check from index 8 to 12

>>>‘This is user_car’.find(‘s’, 8,12 )

9

In order to check special character which is not found in string

.find() function is like .index() function but differ in the next example:

>>> 'This is user_car'.find(‘d’)

-1

>>> 'This is user_car'.index(‘d’)

ValueError



islower () and isupper() functions:

islower() return True if all characters in the string are lowercase and return False otherwise.

[Example]

>>>‘abc’.islower()

True

>>>‘ABc’.islower()

False

>>>‘ABC’.islower()

False




isupper() :

return True if all characters in the string are uppercase and return False otherwise.

Examples:

>>>‘ABC’.isupper()

True

>>>‘AbC’.isupper()

False

>>>‘abc’.isupper()

False




lower() and upper() functions:

Lower (): the function that convert string case into lower case.

Example:

>>>‘This is User Car’.lower()

this is user car

Example:


upper (): the function that convert string case into upper case.

>>>‘This is User Car’.upper ()

THIS IS USER CAR



replace() string function:

This function return a copy of the string with all occurrences of substring old replaced by new.

[Example]

>>>‘This is user car’.replace(‘user’, ‘my’)

This is my car

In order to replace a character many times:

>>>‘This is user car’.replace(‘s’, ‘c’, 3)

'Thic ic ucer car'



strip() string functions:

This function return a copy of the string with the starting orending character removed but If character is not provided, whitespaces will be removed.

Example:

>>>‘ This is my car’.strip()

'This is my car'

>>>‘ This is my car’.strip(‘p’)

'This is a my car'

>>>‘This is my car’.strip(‘r’)

‘This is my ca’


Print and Input functions:

We take and practice print() function which is so simple, now we will take about input() function which store variable data as string

Example:

>>> user_name = input(“Please enter your name”)

Please enter your name

>>> Alex

>>> print(user_name)

Alex

How to deal with string special characters in python?

In order to print string without errors we should use back slash

Character to prevent interfere of these characters with string quotes.

Example:

>>> msg1= “I’m”

>>> msg1= “I\’m”

>>> msg2= “I can’t”

>>> msg2 =" can\’t”

>>> print(msg1+” “ +msg2)

I’m can’t