Python NumPy Programs with Solutions

100 NumPy programs: creating arrays and matrices, element-wise tests and comparisons, indexing, reshaping, sorting, set operations, NaN handling, statistics and rounding. The outputs come from NumPy 2.5; the in-browser Try it uses an older NumPy, so a few printouts may look slightly different.

All programs

• #1Get the NumPy version
  Write a Python program to get the installed NumPy version.Easy
• #2Test that no element is zero
  Write a NumPy program to test whether none of the elements of an array is zero.Easy
• #3Element-wise finite test
  Write a NumPy program to test element-wise whether values are finite.Easy
• #4Element-wise NaN test
  Write a NumPy program to test element-wise for NaN.Easy
• #5Element-wise complex test
  Write a NumPy program to test element-wise for complex numbers.Easy
• #6Element-wise real test
  Write a NumPy program to test element-wise for real numbers.Easy
• #7Is a value a scalar?
  Write a NumPy program to test whether a value is a scalar.Easy
• #8Are two arrays element-wise equal?
  Write a NumPy program to test whether two arrays are element-wise equal.Easy
• #9Element-wise greater than
  Write a NumPy program for an element-wise “greater than” comparison.Easy
• #10Element-wise greater or equal
  Write a NumPy program for an element-wise “greater or equal” comparison.Easy
• #11Element-wise less than
  Write a NumPy program for an element-wise “less than” comparison.Easy
• #12Create an array from values
  Write a NumPy program to create an array with the values 10, 34, 86, 26, 56.Easy
• #13Memory used by an array
  Write a NumPy program to find the memory occupied by an array.Easy
• #14Array of three ones
  Write a NumPy program to create an array of 3 ones.Easy
• #15Integers from 1 to 20
  Write a NumPy program to create an array of integers from 1 to 20.Easy
• #16Even integers from 1 to 20
  Write a NumPy program to create an array of even integers from 1 to 20.Easy
• #17Odd integers from 1 to 20
  Write a NumPy program to create an array of odd integers from 1 to 20.Easy
• #18Integers 1 to 100 in steps of 6
  Write a NumPy program to create an array of integers from 1 to 100 with a difference of 6.Easy
• #193 × 3 matrix
  Write a NumPy program to create a 3 × 3 matrix.Easy
• #203 × 3 identity matrix
  Write a NumPy program to create a 3 × 3 identity matrix.Easy
• #21Random numbers between 1 and 2
  Write a NumPy program to generate random numbers between 1 and 2.Easy
• #22Five standard normal numbers
  Write a NumPy program to generate 5 random numbers from a standard normal distribution.Easy
• #23Vector from 1 to 20
  Write a NumPy program to create a vector with values 1 to 20.Easy
• #24All values except 20
  Write a NumPy program to print all values of the vector 1-20 except 20.Easy
• #25All values except 1
  Write a NumPy program to print all values of the vector 1-20 except 1.Easy
• #263 × 4 matrix
  Write a NumPy program to create a 3 × 4 matrix.Easy
• #272 × 3 matrix
  Write a NumPy program to create a 2 × 3 matrix.Easy
• #282 × 2 matrix
  Write a NumPy program to create a 2 × 2 matrix.Easy
• #29Change the sign of a range
  Write a NumPy program to create a vector of 1 to 15 and change the sign of the numbers from 6 to 10.Easy
• #30Multiply two vectors
  Write a NumPy program to multiply two vectors element-wise.Easy
• #312 × 3 matrix from 5 to 10
  Write a NumPy program to create a 2 × 3 matrix with values from 5 to 10.Easy
• #32Shape of a matrix
  Write a NumPy program to find the shape of a matrix.Easy
• #33Reshape 2 × 3 into 3 × 2
  Write a NumPy program to reshape a 2 × 3 matrix into a 3 × 2 matrix.Easy
• #34Diagonal matrix
  Write a NumPy program to create a 2 × 2 zero matrix with 7 and 8 on the main diagonal.Easy
• #35Sum of all elements
  Write a NumPy program to calculate the sum of all elements.Easy
• #36Sum of each row
  Write a NumPy program to calculate the sum of each row.Easy
• #37Sum of each column
  Write a NumPy program to calculate the sum of each column.Easy
• #38Dot product of two vectors
  Write a NumPy program to calculate the dot product of two vectors.Easy
• #39Add a vector to each row
  Write a NumPy program to add a vector to each row of a matrix.Easy
• #40List to array
  Write a NumPy program to convert a list into an array.Easy
• #41Array to list
  Write a NumPy program to convert an array into a list.Easy
• #42Find missing data
  Write a NumPy program to find the missing (NaN) values in an array.Easy
• #43Element-wise equality
  Write a NumPy program to check whether two arrays are equal element-wise.Easy
• #44One-dimensional array
  Write a NumPy program to create a one-dimensional array.Easy
• #45Transpose a matrix
  Write a NumPy program to swap the rows and columns of a matrix.Easy
• #46Sort each row
  Write a NumPy program to sort each row in ascending order.Easy
• #47Sort rows by the first column
  Write a NumPy program to sort the rows of an array by the first column.Easy
• #48Numbers greater than a value
  Write a NumPy program to extract numbers greater than 6.Easy
• #49Replace numbers at or above a value
  Write a NumPy program to replace numbers greater than or equal to 8 with 0.Easy
• #50Reverse the row order
  Write a NumPy program to swap the rows of an array (first and last).Easy
• #51Multiply a row by a scalar
  Write a NumPy program to multiply row 1 of an array by 2.Easy
• #52Add one row to another
  Write a NumPy program to add row 2 to row 1.Easy
• #53Real and imaginary parts
  Write a NumPy program to find the real and imaginary parts of complex numbers.Easy
• #54Common elements of two arrays
  Write a NumPy program to find the common elements of two arrays.Easy
• #55Unique elements
  Write a NumPy program to get the unique elements of an array.Easy
• #56Set difference
  Write a NumPy program to find the unique values of array1 that are not in array2.Easy
• #57Union of two arrays
  Write a NumPy program to find the union of two arrays.Easy
• #58Index of the maximum
  Write a NumPy program to find the index of the maximum value.Easy
• #59Index of the minimum
  Write a NumPy program to find the index of the minimum value.Easy
• #60Change the data type
  Write a NumPy program to change the data type of an array.Easy
• #61The ith element of a 2-D array
  Write a NumPy program to find the ith element (counting row by row) of a 2-D array.Easy
• #62Remove single-dimensional entries
  Write a NumPy program to remove dimensions of size 1 from a shape.Easy
• #631-D arrays as columns
  Write a NumPy program to combine two 1-D arrays as columns of a 2-D array.Easy
• #64Split into 2, 3 and 5 elements
  Write a NumPy program to split 10 elements into arrays of 2, 3 and 5 elements.Easy
• #65Count non-zero elements
  Write a NumPy program to count the non-zero elements.Easy
• #66Median of a matrix
  Write a NumPy program to find the median of all values in a matrix.Easy
• #67Median of each row
  Write a NumPy program to find the median of each row.Easy
• #68Median of each column
  Write a NumPy program to find the median of each column.Easy
• #69Make an array read-only
  Write a NumPy program to make an array immutable.Easy
• #70Print every element
  Write a NumPy program to print every element of a 2-D array.Easy
• #71Square every element
  Write a NumPy program to print the squares of all elements.Easy
• #72Access by column
  Write a NumPy program to print each column of an array.Easy
• #73Float array to integers
  Write a NumPy program to convert an array of floats to integers.Easy
• #74Add a column
  Write a NumPy program to add an extra column to an array.Easy
• #75Replace negative values
  Write a NumPy program to replace negative values with 1.Easy
• #76Drop rows with NaN
  Write a NumPy program to remove rows that contain NaN.Easy
• #77Magnitude of a vector
  Write a NumPy program to get the magnitude (length) of a vector.Easy
• #78Frequency of unique values
  Write a NumPy program to count how often each unique value appears.Easy
• #79Is an array empty?
  Write a NumPy program to check whether an array is empty.Easy
• #80Product of an array
  Write a NumPy program to calculate the product of an array.Easy
• #81Save an array to CSV
  Write a NumPy program to save an array to a CSV file.Easy
• #82First two columns
  Write a NumPy program to access the first two columns of an array.Easy
• #83Top-left 2 × 2 block
  Write a NumPy program to extract the first and second elements of the first and second rows.Easy
• #84Copy an array
  Write a NumPy program to copy data from one array to another.Easy
• #85Sum of all columns
  Write a NumPy program to calculate the sum of each column.Easy
• #86Row averages ignoring NaN
  Write a NumPy program to calculate the average of each row, ignoring NaNs.Easy
• #87Merge arrays of the same shape
  Write a NumPy program to merge two arrays of identical shape.Easy
• #88Array to a DataFrame with headers
  Write a NumPy program to convert an array into a pandas DataFrame with column headers.Easy
• #89Create and reshape
  Write a NumPy program to create an array and reshape it.Easy
• #90Do two arrays have the same shape?
  Write a NumPy program to check whether two arrays have the same dimensions.Easy
• #91Sine of angles
  Write a NumPy program to calculate the sine of angles.Easy
• #92Standard deviation
  Write a NumPy program to calculate the standard deviation of an array.Easy
• #93Variance
  Write a NumPy program to calculate the variance of an array.Easy
• #94Cosine of angles
  Write a NumPy program to calculate the cosine of angles.Easy
• #95Tangent of angles
  Write a NumPy program to calculate the tangent of angles.Easy
• #96Round to two decimals
  Write a NumPy program to round elements to two decimal places.Easy
• #97Floor of each element
  Write a NumPy program to round elements down with floor.Easy
• #98Ceiling of each element
  Write a NumPy program to round elements up with ceil.Easy
• #99Tuple to array
  Write a NumPy program to convert a tuple into an array.Easy
• #100Complex dtype array
  Write a NumPy program to create an array with complex dtype.Easy