PANDAS SERIES – SUBJECTIVE QUESTIONS WITH ANSWERS (Class XII – Python)
✍️ VERY SHORT ANSWER QUESTIONS (1 MARK)
Q1. What is a Pandas Series?
Ans: A Pandas Series is a one-dimensional labeled array capable of storing data of different data types.
Q2. Write the syntax to create a Pandas Series.
Ans:
pd.Series(data, index)
Q3. Name the Python library used to create Series.
Ans: pandas
Q4. What is the default index of a Series?
Ans: Integer index starting from 0.
Q5. Can a Pandas Series store heterogeneous data?
Ans: Yes, a Pandas Series can store heterogeneous data.
Q6. Write one difference between a list and a Pandas Series.
Ans:
-
List has no index labels, whereas Series has labeled index.
Q7. What is the use of head() function?
Ans: It displays the first few elements of a Series.
Q8. Write the function used to check missing values in a Series.
Ans: isnull() or isna()
Q9. What does dtype attribute represent?
Ans: It represents the data type of the Series.
Q10. Name the function used to remove missing values.
Ans: dropna()
✍️ SHORT ANSWER QUESTIONS (2 MARKS)
Q11. What are the advantages of using Pandas Series?
Ans:
-
Supports labeled indexing
-
Can store heterogeneous data
Q12. How is Pandas Series different from NumPy array?
Ans:
-
Series has index labels, NumPy array does not
-
Series can store mixed data types
Q13. Explain indexing in Pandas Series with an example.
Ans:
Indexing is used to access elements using index labels or positions.
s = pd.Series([10, 20, 30])
print(s[1]) # Output: 20
Q14. What is the use of loc[] and iloc[]?
Ans:
-
loc[]→ Label-based indexing -
iloc[]→ Integer-based indexing
Q15. What are missing values in Pandas?
Ans: Missing values are empty or null values represented by NaN.
Q16. Differentiate between size and count().
Ans:
-
size→ Total elements -
count()→ Non-missing elements only
Q17. Explain fillna() and dropna().
Ans:
-
fillna()replaces missing values -
dropna()removes missing values
Q18. What is Boolean indexing?
Ans: Selecting elements based on True/False conditions.
Q19. How can you change the data type of a Series?
Ans: Using astype() method.
Q20. Write any two statistical functions of Series.
Ans:
-
mean() -
sum()
✍️ SHORT ANSWER QUESTIONS (3 MARKS)
Q21. Create a Series using a list and a dictionary.
Ans:
# Using list
s1 = pd.Series([10, 20, 30])
# Using dictionary
s2 = pd.Series({'A':10, 'B':20})
Q22. What is reindexing? Explain with example.
Ans:
Reindexing means changing or rearranging the index of a Series.
s = pd.Series([10, 20], index=['a','b'])
s = s.reindex(['b','a'])
Q23. Explain mean(), sum() and max().
Ans:
-
mean()→ Average -
sum()→ Total -
max()→ Highest value
Q24. Program to display first three and last two elements.
Ans:
import pandas as pd
s = pd.Series([5, 10, 15, 20, 25])
print(s.head(3))
print(s.tail(2))
Q25. Explain arithmetic operations on Series.
Ans:
Arithmetic operations are vectorized and applied element-wise.
✍️ LONG ANSWER QUESTIONS (5 MARKS)
Q26. What is a Pandas Series? Explain its features with example.
Ans:
A Pandas Series is a one-dimensional labeled array.
Features:
-
Labeled index
-
Heterogeneous data
-
Mutable
-
Vectorized operations
Example:
s = pd.Series([10, 20, 30], index=['a','b','c'])
Q27. Explain different ways of creating a Pandas Series.
Ans:
-
Using list
-
Using dictionary
-
Using NumPy array
pd.Series([1,2,3])
pd.Series({'A':10,'B':20})
Q28. Explain missing values and methods to handle them.
Ans:
Missing values are represented by NaN.
Methods:
-
isnull()– detect -
fillna()– replace -
dropna()– remove
Q29. Explain indexing and slicing using loc[] and iloc[].
Ans:
-
loc[]uses labels -
iloc[]uses integer positions
s.loc['a']
s.iloc[0:2]
Q30. Program using Series to store marks and perform operations.
Ans:
import pandas as pd
marks = pd.Series([78, 85, None, 90])
print("Average:", marks.mean())
print("Highest:", marks.max())
print("Lowest:", marks.min())
print("After removing missing values:")
print(marks.dropna())
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-
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🧪 Most important programs
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📊 Pandas DataFrame subjective questions
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Here are MORE SUBJECTIVE QUESTIONS WITH ANSWERS on PANDAS SERIES, written exactly in Class XII Board-exam style.
(You can directly learn and write these in exams.)
🐍 PANDAS SERIES
MORE SUBJECTIVE QUESTIONS WITH ANSWERS
(Class XII Board Examination)
✍️ VERY SHORT ANSWER (1 MARK)
Q31. What does index attribute return in a Series?
Ans: It returns the index labels of the Series.
Q32. Write the command to display last 5 elements of a Series.
Ans:
s.tail()
Q33. What is the use of values attribute?
Ans: It returns the data values of the Series.
Q34. Which function gives the total number of elements in a Series?
Ans: size
Q35. Name the function used to find maximum value in a Series.
Ans: max()
Q36. Write one use of astype() function.
Ans: It is used to change the data type of a Series.
Q37. What is Boolean indexing?
Ans: Selecting elements of a Series using True/False conditions.
Q38. Which function counts frequency of values?
Ans: value_counts()
Q39. What does empty attribute return?
Ans: It returns True if the Series is empty, otherwise False.
Q40. Can index labels be changed after Series creation?
Ans: Yes, index labels can be changed.
✍️ SHORT ANSWER (2 MARKS)
Q41. Explain head() and tail() functions.
Ans:
-
head()displays first few elements -
tail()displays last few elements
Q42. What is the use of value_counts()?
Ans: It returns the frequency of each unique value in a Series.
Q43. Differentiate between loc[] and iloc[].
Ans:
-
loc[]→ Label-based indexing -
iloc[]→ Integer-based indexing
Q44. What is the purpose of reindex()?
Ans: It is used to change or rearrange index labels of a Series.
Q45. Explain isnull() and notnull().
Ans:
-
isnull()detects missing values -
notnull()detects non-missing values
Q46. How do you check data type of a Series?
Ans: Using dtype attribute.
Q47. Write two features of Pandas Series.
Ans:
-
Labeled indexing
-
Supports vectorized operations
Q48. What is vectorization in Series?
Ans: Performing operations element-wise without using loops.
Q49. Write two methods to handle missing values.
Ans:
-
fillna() -
dropna()
Q50. How is Series different from DataFrame?
Ans:
-
Series → One-dimensional
-
DataFrame → Two-dimensional
✍️ SHORT ANSWER (3 MARKS)
Q51. Explain creation of a Pandas Series with custom index.
Ans:
Custom index allows assigning meaningful labels.
import pandas as pd
s = pd.Series([100, 200, 300], index=['Jan','Feb','Mar'])
Q52. Explain statistical functions of Series.
Ans:
-
mean()→ Average -
sum()→ Total -
min()/max()→ Lowest / Highest
Q53. Explain Boolean indexing with example.
Ans:
s = pd.Series([10, 20, 30])
print(s[s > 15])
Q54. Write a program to replace missing values with zero.
Ans:
import pandas as pd
s = pd.Series([10, None, 30])
print(s.fillna(0))
Q55. Explain sorting in Pandas Series.
Ans:
-
sort_values()→ Sort by values -
sort_index()→ Sort by index
✍️ LONG ANSWER (5 MARKS)
Q56. Explain Pandas Series indexing and slicing with examples.
Ans:
Indexing is accessing individual elements, while slicing accesses a range.
import pandas as pd
s = pd.Series([10, 20, 30, 40], index=['a','b','c','d'])
print(s['b']) # Indexing
print(s[1:3]) # Slicing
Q57. Explain handling missing values in Pandas Series.
Ans:
Missing values are represented by NaN.
Methods:
-
isnull()– Detect -
fillna()– Replace -
dropna()– Remove
Q58. Write a program to perform arithmetic operations on Series.
Ans:
import pandas as pd
s = pd.Series([5, 10, 15])
print(s + 2)
print(s * 3)
Q59. Explain the advantages of Pandas Series over Python list.
Ans:
-
Labeled indexing
-
Faster operations
-
Handles missing values
-
Built-in statistical functions
Q60. Write a complete program using Series to analyze marks of students.
Ans:
import pandas as pd
marks = pd.Series([75, 82, None, 90, 85])
print("Marks:")
print(marks)
print("Average:", marks.mean())
print("Highest:", marks.max())
print("Lowest:", marks.min())
print("After removing missing values:")
print(marks.dropna())
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