Part 8- Library Function
Library Function are also known as built in functions, they are functions already present in the Python library.
Advantages of Library
Function
1.
Saves
time
2.
Increase
Productivity
3.
Improves
code readability
4.
Easy
to debug
1. pow()
pow() function is
used to calculate the power of a given number.
Syntax:
pow(base, exponent)
Example:
result = pow(2, 3)
print(result)
2. sqrt()
sqrt() function is used to return the
square root of a given number.
(It is available in the math
module.)
Syntax:
import math
math.sqrt(number)
Example:
import math
result =
math.sqrt(25)
print(result)
3. int()
int() function is used to convert a
number or string into an integer value.
Syntax:
int(value)
Example:
num = int(5.8)
print(num)
4. abs()
abs() function is
used to return the absolute (positive) value of a number.
Syntax:
abs(number)
Example:
result = abs(-10)
print(result)
5. round()
round() function is
used to round a number to a specified number of decimal places.
Syntax:
round(number, digits)
number → the number to
round
digits → number of
decimal places (optional)
Example
1 (With decimal places):
result = round(5.6789, 2)
print(result)
Example
2 (Without decimal places):
result = round(5.4)
print(result)
Python String
function
1. len()
len() function is used to count the
number of characters in a string.
Syntax:
len(string)
Example:
text = "Python"
result = len(text)
print(result)
2. upper()
upper() function is
used to convert all characters of a string into uppercase.
Syntax:
string.upper()
Example:
text = "hello"
result =
text.upper()
print(result)
3. lower()
lower() function is
used to convert all characters of a string into lowercase.
Syntax:
string.lower()
Example:
text = "PYTHON"
result =
text.lower()
print(result)
4. center()
center() function is
used to align a string at the center within a specified width.
Syntax:
string.center(width,
fillchar)
width → Total width
of the string
fillchar → Optional
character to fill empty space
Example:
text = "Python"
result =
text.center(12, "*")
print(result)
Work out example
1.
To
calculate square root of a given number
import math
num = float(input("Enter
a number: "))
result =
math.sqrt(num)
print("Square
root =", result)
2.
To
count number of characters present in the given word
word = input("Enter
a word: ")
print("Number
of characters =", len(word))
3.
To
convert given word in uppercase
word = input("Enter
a word: ")
print("Uppercase
word =",
word.upper())
4.
To
display longest word among two different words
word1 = input("Enter
first word: ")
word2 = input("Enter
second word: ")
if len(word1) > len(word2):
print("Longest
word =", word1)
else:
print("Longest
word =", word2)
5.
To
display square and cube of the given number
num = int(input("Enter
a number: "))
print("Square
=", num ** 2)
print("Cube
=", num ** 3)
6.
To
count number of vowels present in a given word
word = input("Enter
a word: ").lower()
count = 0
for ch in word:
if ch in "aeiou":
count += 1
print("Number
of vowels =", count)
7.
To
display the given word in reverse order
word = input("Enter
a word: ")
print("Reversed
word =", word[::-1])
8.
To
check whether the given word is palindrome or not
word = input("Enter
a word: ")
if word == word[::-1]:
print("Palindrome")
else:
print("Not
Palindrome")
9.
To
display alternate character of the given word
word = input("Enter
a word: ")
print("Alternate
characters =", word[::2])
10.
To
count space in the given sentence
sentence = input("Enter
a sentence: ")
print("Number
of spaces =", sentence.count(" "))
11.
To
count number of words in the given sentence
sentence = input("Enter
a sentence: ")
words =
sentence.split()
print("Number
of words =", len(words))
Book exercise Page number 300
1. To calculate the
square root of a given number.
import math
num = float(input("Enter a
number: "))
result = math.sqrt(num)
print("Square root =",
result)
2. To display the
longest word among three different words.
word1 = input("Enter first word: ")
word2 = input("Enter second word: ")
word3 = input("Enter third word: ")
longest = word1
if len(word2) > len(longest):
longest = word2
if len(word3) > len(longest):
longest = word3
print("Longest word is:", longest)
3. To convert the given
word into lower case.
word = input("Enter a word:
")
print("Lower case:",
word.lower())
4. To count the number
of characters present in the given word.
word = input("Enter a word:
")
print("Number of
characters:", len(word))
5. To display the square
root of all the even numbers from 2 to 20.
import math
for num in range(2, 21, 2):
print("Square root of", num, "=", math.sqrt(num))
6. To display the cube
of numbers from 1 to 10.
for num in range(1, 11):
print("Cube of", num, "=", num**3)
7. To display the shortest
word among two different words.
word1 = input("Enter first
word: ")
word2 = input("Enter second
word: ")
if len(word1) < len(word2):
print("Shortest word is:", word1)
else:
print("Shortest word is:", word2)
8. To count the number
of consonants present in the given word.
word = input("Enter a word:
")
count = 0
for ch in word:
if ch.isalpha() and ch.lower() not in "aeiou":
count += 1
print("Number of
consonants:", count)
9. To count the number
of characters N/n present in the given word.
word
= input("Enter a word: ")
count
= 0
for
ch in word:
if ch == 'N' or ch == 'n':
count += 1
print("Number
of N/n:", count)
10.
To display the string in the following pattern
PROGRAM
PROGRA
PROGR
PROG
PRO
PRO
PR
P
word
= "PROGRAM"
for
i in range(len(word), 0, -1):
print(word[:i])
N
NE
NEP
NEPA
NEPAL
word
= "NEPAL"
for
i in range(1, len(word), + 1):
print(word[:i])