NumPy Basic

1. What is NumPy in Python primarily used for ?
   1. Web development
   2. Data visualization
   3. Scientific computing and data analysis
   4. Machine learning algorithms
   Show Answer

   Answer : C
   Explain : NumPy is stands for Numerical Pyhton. It is used for working with arrays.
2. Which of the following data structure is a core component of NumPy ?
   1. List
   2. Dictionary
   3. Tuple
   4. ndarray (N-dimensional array)
   Show Answer

   Answer : D
   Explain : ndim is used to display the dimension of array.
3. How can you create a 1D array in NumPy ?
   1. numpy.array([1, 2, 3])
   2. numpy.ndarray(1, 2, 3)
   3. numpy.list([1, 2, 3])
   4. numpy.array(1, 2, 3)
   Show Answer

   Answer : A
   Explain : One dimensional array contains elements only in one dimension.
4. Solve the given code ?

   import numpy as n
   a= n.array([1,2,3])
   b= n.array([1,2,3])
   c=a+b
   print(c)
   

   1. [2,4,6]
   2. [1,2,3]
   3. [1,2,3]
   4. [2 4 6]
   Show Answer

   Answer : D
   Explain : print(c) means we want to print the array so array come in [] without comma.
5. What will be output of following code ?

   import numpy as n
   nb=n.arange(4)
   print(nb)
   

   1. [0 1 2 3]
   2. [0 1 2 3 4]
   3. [0, 1, 2, 3]
   4. None of the above
   Show Answer

   Answer : A
   Explain : It gives value in array.
6. What will be the output of following code ?

   import numpy as n
   print(n.minimum([2,3,4],[1,5,2]))
   

   1. [1 2 5]
   2. [1 5 2]
   3. [2 3 4]
   4. [1 3 2]
   Show Answer

   Answer : D
   Explain :It check the value minimum. Like 2 or 1 min. is 1, 3 or 5 min. is 3 , 4 or 2 min. is 2.
7. Solve the given code :

   import numpy as np
   a=np.array([1,2,1,5,8])
   b=np.array([0,1,5,4,2])
   c=a+b
   c=c*a
   print(c[2])
   

   1. 6
   2. 10
   3. 0
   4. None of above
   Show Answer

   Answer : A
   Explain : First it sum c =a+b=[ 1 3 6 9 10] Then c*a=[ 1 6 6 45 80]. At, last print(c[2]) index value c[2] is 6
8. What are the attributes of numpy array ?
   1. shape, dtype, ndim
   2. object, type, list
   3. objects, non, vectorization
   4. Unicode and shape
   Show Answer

   Answer : A
   Explain : ndim, shape, size, dtype, reshape are the attributes os numpy.
9. how can we check all fucntion in numpy ?
   1. import numpy
      print(dir(numpy))
   2. import numpy
      print(info(numpy))
   3. import numpy
      print((numpy.list))
   4. None of the above
   Show Answer

   Answer :A
   Explain :The dir() function returns all properties and methods of the specified object, without the values.
10. Which NumPy function is used to create an array filled with zeros ?
    1. empty()
    2. zeros()
    3. ones()
    4. copy()
    Show Answer

    Answer : B
    Explain : zeros() creates an array filled with zero.
11. The primary purpose of the copy() function in NumPy is to :
    1. Create an empty array
    2. Create an array with ones
    3. Duplicate an existing array with its data
    4. Create an array with zeros
    Show Answer

    Answer : C
    Explain : copy() used to copy array.
12. What is the output of following code ?

    import numpy as np 
    a=np.array([12,22,33,44])
    print(a.dtype)
    

    1. int
    2. integer
    3. int32
    4. None of above
    Show Answer

    Answer : C
    Explain : int32 means that it contain integer value.Int32 is an immutable value type that represents signed integers with values
13. Can we convert tuple in array ?
    1. Yes
    2. No
    3. Can't say
    4. May be
    Show Answer

    Answer : A
    Explain : Yes, we can convert tuple in array.
14. What will be the output of following code ?

    import numpy as np 
    arr = np.array([[1, 2, 3, 4],[45, 64, 47, 48]])
    print(arr.shape)
    	
    

    1. (3, 4)
    2. (4, 4)
    3. (2, 4)
    4. (4, 2)
    Show Answer

    Answer : C
    Explain : Here is 2 row and 4 element in it. It is 2-D (2 dimensional).
15. What will be output for the following code ?
    import numpy as np
    a = np.array([[1,2,3],[0,1,4],[11,22,33]])
    print (a.size)
    1. 1
    2. 3
    3. 4
    4. 9
    Show Answer

    Answer : D
    Explain : size method returns the total number of elements of in an array.