Introduction to Python
Component of Python
String here in Python used to define unicode characters. There is no special character data type , a single character in Python is just a string of length of 1.
Here in Python , string can be written in the form of single quotation or double quotation that means ‘Hello’ =”Hello”. And string can also be output too if it is used in print function.
For example:-
print("Hello World")
print('Hello World')
In above program we just gave command of printing ‘Hello World ’ by using single quotation and double quotation .
Let’s see whether it works or not :-
So both are working that means we can use both double quotation or single quotation to use string in our program.
1. Python gives us the ease to select any particular character from the string if we want .
For this we have to used square brackets [] to access the element. But here the first element has index or position 0.
For example :-
Get the character at position 4 of ‘Hello world’?
a="Hello world"
print(a[4])
As we have earlier discussed that the first character have the position or index ‘0’ . So let’s see what happens after giving command of getting the character which is having 4th position .
So here it prints ‘O’ character because it comes on the position 4 after taking 1st character as position ‘0’
2. In Python we can also choose substring from any position to any. Let us understand this by following example :-
Get the character from position 2 to position 6 (not included)?
a="Hello world"
print(a[2:6])
Here in above program we are giving command to Python that we want the substring from the position 2 to position 6 . So let’s see what happens :-
So here we just got the output which comes under position 2 to position 6.It also includes spaces if there are so.
3. If in case we want to skip some character in any substring than also through the help of slicing we can do that . Let’s understand this by example :-
Get the elements by skipping 1 character from the string
a="Hello world"
print(a[0:12:2])
Here in above program we just gave command to our Python interpreter that from the word “Hello word ” we want to extract the word by skipping the next word. So let’s see…
So here as we can see , we are getting the words by skipping the next word. Like this we can skip as much words we want.
Methods are basically the function which we want to perform in our coding . In Python there are some inbuilt methods are there for String .
So let’s see some of them :-
1. The len() method returns the length of a string
a = "Hello world"
print(len(a))
So here we just get the length of our string.
2. The lower() method returns the whole string in lower letters.
a = "Hello world"
print(a.lower())
So here we just get our whole string in lower letters.
3. The type () method returns basically the type of the data type.
a = "Hello world"
print(type(a))
So here we just get the data type .
So here we are enlisting some methods and their description which we can use in Python.
METHOD | DESCRIPTION |
---|---|
capitalize() | Converts the first character to uppercase |
casefold() | Converts string into lower case |
center() | Returns a centered string |
count() | Returns the number of times a specified value occurs in a string |
encode() | Returns an encoded version of the string |
endswith() | Returns true if the string ends with the specified value |
expandtabs() | Set the tab size of string |
find() | Searches the string for a specified value and returns the position of where it was found |
format() | Formats specified values in a string |
format_map() | Formats specified values in a string |
index()) | Searches the string for a specified value and returns the position of where it was found |
isalnum() | Returns True if all characters in the string are alphanumeric |
isalpha() | Returns True if all characters in the string are in the alphabet |
isdecimal() | Returns True if all characters in the string are decimals |
isdigit() | Returns True if all characters in the string are digits |
isidentifier() | Returns True if the string is an identifier |
islower() | Returns True if all characters in the string are in lower case |
isnumeric() | Returns True if all characters in the string are numeric |
isprintable() | Returns True if all characters in the string are printable |
isspace() | Returns True if all characters in the string are whitespaces |
istitle() | Returns True if the string follows the rules of a title |
isupper() | Returns True if all characters in the string are in upper case |
join() | Joins the elements of an iterable to the end of the string |
|just() | Returns a left justified version of the string |
lower() | Converts a string into lower case |
|strip() | Returns a left trim version of the string |
maketrans() | Returns a translation table to be used in translations |
partition() | Returns a tuple where the string is divided into three parts |
replace() | Returns a string where a specified value is replaced with a specified value |
rfind() | Searches the string for a specified value and returns the last position of where it was found |
rindex() | Searches the string for a specified value and returns the last position of where it was found |
rjust() | Returns a right justified version of the string |
rpartition() | Returns a tuple where the string is divided into three parts |
rsplit() | Splits the string at the specified separator, and returns a list |
rstrip() | Returns a right trim version of the string |
split() | Splits the string at the specified separator, and returns a list |
splitlines() | Splits the string at line breaks and returns a list |
startswith() | Returns true if the string starts with the specified value |
strip() | Returns a trimmed version of the string |
swapcase() | Swaps cases, lower case becomes upper case and vice versa |
title() | Converts the first character of each word to uppercase |
translate() | Returns a translated string |
upper() | Converts a string into upper case |
zfill() | Fills the string with a specified number of 0 values at the beginning |
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