String Commands
In the python programming language, there are various string commands which are used on string objects. These commands do not change the original string object, they just return a new object. Some of the most important string functions are:
isalnum()
It checks whether all the characters of a given string are alphanumeric or not. It returns a boolean value.
Syntax: stringname.isalnum()
capitalize()
capitalize() function changes the first character of the string to uppercase if it’s lowercase. If the first character is uppercase or an integer or any special character, it doesn’t do anything.
Syntax: stringname.capitalize()
find()
find() command is used to search for a substring in a string. It returns the index of the first occurrence of the substring if it is present otherwise it returns -1.
Syntax: string.find(substring)
- string refers to the string in which you want to search.
- substring refers to the value that you want to search.
count()
count() function returns the count of occurrences of a substring in a string object.
Syntax: stringname.count(substring, start, end)
- stringname refers to the string in which you want to search.
- substring refers to the value whose count you want to find.
- start refers to that starting index within the string where search starts (Optional)
- end refers to that ending index within the string where the search ends (Optional)
center()
center command is used to align a string in the center, using a specified character (by default it is space) as the fill character.
Syntax: string.center(length, character)
- string is the string that you want to align in center
- length is the full length taken by the new string in which both sides will be filled by character and in the center, we will have the original string.
- character refers to the character used to fill the missing space on each side. Default is ” ” (space).
List Commands
Just like a string we have various commands for list objects as well. Lists are used to multiple elements in a single object. We can use lists to store elements of different data types. Some of the most important list methods are:
append()
append() command is used to add an element at the end of the list.
Syntax: list.append(element)
- list is the list object in which you want to add an element
- element refers to the new item that you want to add to the list
copy()
copy() is used to create a new copy of the list object. It returns a new list object.
Syntax: list.copy()
insert()
insert() command is used to add an element at a specified position in the list object. It takes two parameters position and element.
Syntax: listname.insert(position, element)
- position at which you want to insert a new element. If you give a position greater than the number of elements in the list, it will always insert at the end.
- element refers to the new element that needs to be added.
pop()
pop() method is used to remove an element from a specified position in the list. It returns the element after removing it from the list.
Syntax: listname.pop(position)
position from which you want to remove the element.
reverse()
reverse() method reverses the order of all elements in the list. It modifies the original list object and it doesn’t return anything.
Syntax: list.reverse()
sort()
sort() method is used to sort the elements of the list in ascending order by default.
Syntax: list.sort()
Tuple Commands
Tuple is a built-in data type that is used to store multiple elements in a single variable. Tuple objects are ordered, and immutable. There are only two built-in tuple methods which are as follows:
count(): count method is used to count the occurrences of an element in the tuple.
Syntax: tuple.count(element)
index()
This method is used to find the index of the first occurrence of an element. If the element is not found in the whole tuple then it will raise a ValueError.
Syntax: tuple.index(element)
- tuple is the tuple object in which you want to search an element
- element refers to the item that you wanna search