Python has an in-built function isdigit() which returns true if all characters in a string are digit (between 0-9)>>> string='9764135408' >>> string.isdigit() True >>> string='091-9764135408' >>> string.isdigit() FalseYou can also use regex expression to check if string contains digits only.>>> import re >>> bool(re.match('^[0-9]+$', '9764135408')) True >>> bool(re.match('^[0-9]+$', '091-9764135408')) FalseRead More

The random module in Numpy package contains many functions for generation of random numbersnumpy.random.rand() − Create an array of the given shape and populate it with random samples>>> import numpy as np >>> np.random.rand(3, 2) array([[0.10339983, 0.54395499], [0.31719352, 0.51220189], [0.98935914, 0.8240609 ]])numpy.random.randn() − Return a sample (or samples) from the ... Read More

Floor and modulus operators (// and % respectively) are not allowed to be used on complex number in Python 3.x. However, these operations are defined for complex numbers in Python 2.7.xPython 3>>> x=9+2j >>> y=2+1j >>> x%y Traceback (most recent call last): File "", line 1, in x%y TypeError: ... Read More

By using a temporary variable −>>> x=10 >>> y=20 >>> z=x >>> x=y >>> y=z >>> x,y (20, 10)Without using temporary variable>>> a,b=5,7 >>> a,b (5, 7) >>> a,b=b,a >>> a,b (7, 5)

 LCM (Least common multiple) of two (or more) numbers is a number which is the smallest number that is divisible by both (or all).First we find the larger number of two given numbers. Starting from it we try and find the first number that is divisible by both, which is ... Read More

Python dictionary is collection of key value pairs. Value associated with a certain key is returned by get() method.>>> D1={'a':11,'b':22,'c':33} >>> D1.get('b') 22You can also obtain value by using key inside square brackets.>>> D1['c'] 33

The keys() method of Python dictionary class returns a view object consisting of keys used in the dictionary.>>> d1 = {'name': 'Ravi', 'age': 21, 'marks': 60, 'course': 'Computer Engg'} >>>d1.keys() dict_keys(['name', 'age', 'marks', 'course'])It can be stored as a list object. If new key-value pair is added, the view object ... Read More

If sum of cubes of individual digits in a number add up to the number itself, it is called armstrong number. for example 153=1**3+5**3+3**3ExampleFollowing Python program find armstrong numbers between 100 to 1000for num in range(100, 1000):   temp=num   sum=0   while temp>0:       digit=temp%10     ... Read More

You can use while loop to successively increment value of a variable i by one and adding it cumulatively.s,i=0,0 n=10 while i

Factorial of a number is product of all numbers from 1 to that number.A function is called a recursive function if it calls itself.In following program factorial() function accepts one argument and keeps calling itself by reducing value by one till it reaches 1.Exampledef factorial(x):     if x==1:   ... Read More