CBSE Class 12 Informatics Practices Data Handling using Pandas Worksheet

QUESTION AND ANSWER SECTION

Question. What will be the output of following codeimport pandas as pd
s1=pd.Series([1,2,2,7,’Sachin’,77.5])
print(s1.head())
print(s1.head(3))
Answer:
0  1
1  2
2  2
3  7
4 Sachin
dtype: object
0  1
1  2
2  2
dtype: object

Question. Write a program to display only those values greater than 200 in the given Series “S1”
0 300
1 100
2 1200
3 1700
Answer:
import pandas as pd
S1 = pd.Series([300, 100, 1200, 1700])
print(S1[S1>200])

Question. In pandas, S is a series with the following result:
S=pd.Series([5,10,15,20,25])
The series object is automatically indexed as 0,1,2,3,4. Write a statement to
assign the series as a, b, c, d, e index explicitly.
Answer:
S=pd.Series([5,10,15,20,25],index=['a','b','c','d','e'])

Question. Name any two attributes of Series in Python
Answer: Two attributes of Series in Python are :
1. index
2. values

Question. Write the output of the following :
import numpy as num
import pandas as pd
arr=num.array([1,7,21])
S1 = pd.Series(arr)
print(S1)
Answer:
0   1
1   7
2   21
dtype: int32

Question. Which property of series return all the index value?
Answer: index property return all the index value

Question. Write the output of the following :
import pandas as pd
S1 = pd.Series(range(1,15,3), index=[x for x in "super"])
print(S1)
Answer:
s   1
u  4
p  7
e  10
r   13
dtype: int64

Question. Complete the code to get the required output :
import ______ as pd
________ = pd.Series([31, 28, 31], index = ["Jan", "Feb", "Mar"] )
print(S1["_______"])
OUTPUT :
28
Answer:
import pandas as pd
S1 = pd.Series([31,28,31], index = ["Jan","Feb","Mar"])
print(S1["Feb"])

Question. Write the output of the following code :
import pandas as pd
S1 = pd.Series([31, 28, 31, 30, 31], index = ["Jan", "Feb", "Mar", "Apr", "May"])
print("-----------")
print(S1[1:3])
print("-----------")
print(S1[:5])
print("-----------")
print(S1[3:3])
print("-----------")
print(S1["Jan":"May"])
Answer:
-----------
Feb 28
Mar 31
dtype: int64
-----------
Jan 31
Feb 28
Mar 31
Apr 30
May 31
dtype: int64
-----------
Series([ ], dtype: int64)
-----------
Jan 31
Feb 28
Mar 31
Apr 30
May 31
dtype: int64

DATA FRAMES

Question. What are the purpose of following statements-
1.df.columns
2. df.iloc[ : , :-5]
3. df[2:8]
4. df[ :]
5. df.iloc[ : -4 , : ]
Answer:
1. It displays the names of columns of the Dataframe.
2. It will display all columns except the last 5 columns.
3. It displays all columns with row index 2 to 7.
4. It will display entire dataframe with all rows and columns.
5. It will display all rows except the last 4 four rows

Question. What will be the output of df.iloc[3:7,3:6]?
Answer: It will display the rows with index 3 to 6 and columns with index 3 to 5 in a dataframe ‘df’.

Question. Write a python program to create a data frame with headings (CS and IP) from the list given below-
[[79,92][86,96],[85,91],[80,99]]
Answer:
l=[[10,20],[20,30],[30,40]]
df=pd.DataFrame(l,columns=['CS','IP'])
print(df)

Question. Write python statement to delete the 3rd and 5th rows from dataframe df.
Answer: df1=df.drop(index=[2,4],axis=0)
or
df1=df.drop([2,4])

MCQ QUESTIONS

Question. To display the 3rd, 4th and 5th columns from the 6th to 9th rows of a dataframe you can write
a. DF.loc[6:9, 3:5]
b. DF.loc[6:10, 3:6]
c. DF.iloc[6:10, 3:6]
d. DF.iloc[6:9, 3:5]
Answer: C

Question. We can add a new row to a DataFrame using the _____________ method
a. rloc[ ]
b. loc[ ]
c. iloc[ ]
d. None of the above
Answer: B

Question. The head() function of dataframe will display how may rows from top if no parameter is passed.
a. 1
b. 3
c. 5
d. None of these
Answer: C

Question. To change the 5th column's value at 3rd row as 35 in dataframe DF, you can write
a. DF[4, 6] = 35
b. DF.iat[4, 6] = 35
c. DF[3, 5] = 35
d. DF.iat[3, 5] = 35
Answer: D

Question. Which function is used to find values from a DataFrame D using the index number?
a. D.loc
b. D.iloc
c. D.index
d. None of these
Answer: B

Question. In a DataFrame, Axis= 0 represents the elements
a. rows
b.columns
c. both
d. None of these.
Answer: A

Question. In DataFrame, by default new column added as the _____________ column
a. First (Left Side)
b. Second
c.Last (Right Side)
d. Any where in dataframe
Answer: C

Question. Which of the following is correct Features of DataFrame?
a. Potentially columns are of different types
b. Can Perform Arithmetic operations on rows and columns
c. Labeled axes (rows and columns)
d. All of the above
Answer: D

Question. Write the code to append df2 with df1
a.Df2=Df2.append(Df1)
b. Df2=Df2+Df1
c. Df2=Df2.appendwith.Df1
d. Df2=Df1.append(Df1)
Answer: A

Question. When we create DataFrame from List of Dictionaries, then number of columns in DataFrame isequal to the _______
a. maximum number of keys in first dictionary of the list
b. maximum number of different keys in all dictionaries of the list
c. maximum number of dictionaries in the list
d. None of the above
Answer: B

Question. When we create DataFrame from List of Dictionaries, then dictionary keys will become ______
a. Column labels
b. Row labels
c. Both of the above
d. None of the above
Answer: A

Question. Which method is used to access vertical subset of a dataframe?
a. iterrows()
b. iteritems()
c. itercolumns()
d. itercols()
Answer: B

Question. Write statement to transpose dataframe DF.
a. DF.t
b. DF.transpose
c.DF.T
d.DF.T( )
Answer: C

Question. In DataFrame, by default new column added as the _____________ column
a. First (Left Side)
b. Second
c. Last (Right Side)
d. Any where in dataframe
Answer: C

Question. We can add a new row to a DataFrame using the _____________ method
a. rloc[ ]
b. loc[ ]
c. iloc[ ]
d. None of the above
Answer: B

Question. Which of the following function is used to load the data from the CSV file to DataFrame?
a. read.csv( )
b. readcsv( )
c. read_csv( )
d. Read_csv( )
Answer: C

Question. Which of the following function is not a Boolean reduction function
a. Empty
b. Any()
c. All()
d. Fillna()
Answer: D

Question. Which among the following options can be used to create a DataFrame in Pandas ?
a. A scalar value
b. An ndarray
c. A python dict
d. All of these
Answer: D

Question. Which attribute of a dataframe is used to convert row into columns and columns into rows in a dataframe?
a. T
b. ndim
c. empty
d. shape
Answer: A

Question. When we create DataFrame from List of Dictionaries, then number of columns in DataFrame is equal to the _______
a. maximum number of keys in first dictionary of the list
b. maximum number of different keys in all dictionaries of the list
c. maximum number of dictionaries in the list
d. None of the above
Answer: B

Question. Which of the following is/are characteristics of DataFrame?
a. Columns are of different types
b. Can Perform Arithmetic operations
c. Axes are labeled (rows and columns)
d. All of the above
Answer: D

Question. Write short code to show the information having city=”Delhi” from dataframe SHOP.
a. print(SHOP[City==’Delhi’])
b. print(SHOP[SHOP.City==’Delhi’])
c. print(SHOP[SHOP.’City’==’Delhi’])
d. print(SHOP[SHOP[City]==’Delhi’])
Answer: B

Question. Which of the following commands is used to install pandas?
a. pip install python –pandas
b. pip install pandas
c. python install python
d. python install pandas
Answer: B

Question. Assuming the given structure, which command will give us the given output:
Output Required: (3,4)
EmpCode Name Desig
0 1405 VINAY Clerk
1 1985 MANISH Works Manager
2 1636 SMINA Sales Manager
3 1689 RINU Cleark
a. print(df.shape())
b. print(df.shape)
c. print(df.size)
d. print(df.size()).
Answer: B

Question. Write the output of the given command: df1.loc[:0,'Name'] Consider the given dataframe.
EmpCode Name Desig
0 1405 VINAY Clerk
1 1985 MANISH Works Manager
2 1636 SMINA Sales Manager
3 1689 RINU Clerk
a. 0 1405 VINAY Clerk
b. VINAY
c. Works Manager
d. Clerk
Answer: B

Question. which one of these is not a valid line style in matplotlib
a. ‘-‘
b. ‘--‘
c. ‘-.’
d. ‘<’
Answer: D

Question. How can we make bar chart horizontal?
a. plt.bar()
b. plt.hbar()
c. plt.barh()
d. plt.rightbar()
Answer: C

Question. A histogram is used:
a. for continuous data
b. for grouped data
c. for time series data
d. to compare two sets of data
Answer: A

Question. Which function is used to show legend ?
a. display ( )
b. show( )
c. legend( )
d. legends( )
Answer: C

Question. The datapoints plotted on a graph are called _____________
a. Markers
b. Values
c. Ticks
d. Pointers
Answer: A 

Question. To specify the style of line as dashed , which argument of plot() needs to be set ?
a. line
b. width
c. Style
d. linestyle
Answer: D

Question. Which of the following is not a valid plotting function in pyplot?
a. bar()
b. hist()
c. histh()
d. barh()
Answer: C

Question. To get top 5 rows of a dataframe, you may use
a. head( )
b. head(5)
c. top( )
d. top(5)
Answer: A

Question. The correct statement to read from a CSV file in a dataframeis :
a. .read_csv()
b. . read_csv( )()
c. = pandas.read()
d. = pandas.read_csv()
Answer: D

Question. To delete a column from a dataframe, you may use ______ statement.
a. remove()
b. del()
c. drop()
d. cancel()
Answer: C

Question. To get top 5 rows of a dataframe, you may use
a. head( )
b. head(5)
c. top( )
d. top(5)
Answer: A

Question. To iterate over horizontal subsets of dataframe,
a. iterate( )
b. iterrows( ) function may be used.
c. itercols( )
d. iteritems( )
Answer: B

Question. Write code to delete the row whose index value is A1 from dataframe df.
a. df=df.drop(‘A1’)
b. df=df.drop(index=‘A1’)
c. df=df.drop(‘A1,axis=index’)
d. df=df.del(‘A1’)
Answer: A

Question. A two-dimension labelled array that is an ordered collection of columns to store heterogeneous datatype is
a. Series
b. Numpy array
c. Dataframe
d. Panel
Answer: C

Importing/Exporting Data between CSV files and Data Frames Basics of CSV Files

Question. Read the statements given below and identify the right option to draw a histogram.
Statement A: To make a Histogram with Matplotlib, we can use the plt.hist() function.
Statement B: The bin parameter is compulsory to create histogram.
a. Statement A is correct
b. Statement B is correct
c. Statement A is correct, but Statement B is incorrect
d. d. Statement A is incorrect, but Statement B is correct
Answer: D

Question. Which graph should be used where each column represents a range of values, and the height of a column corresponds to how many values are in that range?
a. plot
b. line
c. bar
d. histogram
Answer: D

Question. To give a title to x-axis, which of the following method is used?
a. plt.xtitle(“title”)
b. plt.xlabel(“title”)
c. plt.xheader(“title”)
d. plt.xlabel.show(“title”)
Answer: A

Question. To change the width of bars in bar chart, which of the following argument with a float value is used?
a. thick
b. thickness
c. width
d. barwidth
Answer: C

Question. What is the purpose of legend?
a. A legend is an area describing the elements of the graph.
b. A legend is top area with information about graph
c. A legend is additional information of x and y labels
d. A legend is a mini box with bars data
Answer: A