Commerce (English Medium) Class 12 - CBSE Important Questions for Computer Science (Python)

Write one difference between CSV and text files.

Write a program in Python that defines and calls the following use of defined functions:

1. COURIER_ADD(): It takes the values from the user and adds the details to a CSV file 'courier.csv’. Each record consists of a list with field elements as cid, s_name, Source, destination to store Courier ID, Sender name, Source, and destination address, respectively.
2. COURIER SEARCH(): Takes the destination as the input and displays all the courier records going to that destination. 

Why it is important to close a file before exiting?

Which of the following functions changes the position of file pointer and returns its new position?

Write a function, lenWords(STRING), that takes a string as an argument and returns a tuple containing length of each word of a string.
For example, if the string is "Come let us have some fun", the tuple will have (4, 3, 2, 4, 4, 3)

Write a function in Python to read a text file, Alpha.txt and displays those lines which begin with the word ‘You’.

Write a function, vowelCount() in Python that counts and displays the number of vowels in the text file named Poem.txt.

Select the correct output of the code:

S="Amrit Mahotsav @ 75"
A=S.partition (" ")
print(a)

Differentiate between r+ and w+ file modes in Python.

Consider a file, SPORT.DAT, containing records of the following structure:

[SportName, TeamName, No_Players]

Write a function, copyData(), that reads contents from the file SPORT.DAT and copies the records with Sport name as “Basket Ball” to the file named BASKET.DAT. The function should return the total number of records copied to the file BASKET.DAT.

A Binary file, CINEMA.DAT has the following structure:

{MNO:[MNAME, MTYPE]}

Where

• MNO - Movie Number
• MNAME - Movie Name
• MTYPE is Movie Type

Write a user defined function, findType(mtype), that accepts mtype as parameter and displays all the records from the binary file CINEMA.DAT, that have the value of Movie Type as mtype.

Vedansh is a Python programmer working in a school. For the Annual Sports Event, he has created a csv file named Result.csv, to store the results of students in different sports events. The structure of

Result.csv is:

[St_Id, St_Name, Game_Name, Result]

Where

St_Id is Student ID (integer)

ST_name is Student Name (string)

Game_Name is name of game in which student is participating(string). Result is result of the game whose value can be either 'Won', 'Lost' or 'Tie'.

For efficiently maintaining data of the event, Vedansh wants to write the following user defined functions:

Accept() - to accept a record from the user and add it to the file

Result.csv. The column headings should also be added on top of the csv file.

wonCount() - to count the number of students who have won any event.

As a Python expert, help him complete the task.

How are text files different from binary files?

How are text files different from binary files?

Observe the following tables VIDEO and MEMBER carefully and write the name of the RDBMS operation out of (i) SELECTION (ii) PROJECTION (iii) UNION (iv) CARTESIAN PRODUCT, which has been used to produce the output as shown below. Also, find the
Degree and Cardinality of the final result.

TABLE: VlDEO

TABLE: MEMBER

TABLE: FINAL RESULT

Write SQL queries for (i) to (iv) and find outputs for SQL queries (v) to (viii) which are based on the table.

TABLE: Account

TABLE: TRANSACT

1) To display details of all transaction of TYPE Depos1t from Table TRANSACT.

2) To display the ANO and AMOUNT of all Depos1ts and Withdrawals done in the month of October 2017 from table TRANSACT.

3) To display the last date of the transaction (DOT) from the table TRANSACT for the Accounts having ANO as 103

4) To display all ANO, ANAME and DOT of those persons from tables ACCOUNT and TRANSACT who have done transactions less than or equal to 3000?

5) SELECT ANO, ANAME FROM ACCOUNT WHERE ADDRESS NOT IN ('CHENNAI', 'BANGALORE');

6) SELECT DISTINCT ANO FROM TRANSACT

7) SELECT ANO, COUNT(*), MIN(AMOUNT) FROM TRANSACT GROUP BY AND HAVING COUNT(*) > 1;

8) SELECT COUNT(*), SUM(AMOUNT) FROM TRANSACT WHERE DOT <= '2017-06-01'

Observe the following table MEMBER carefully and write the name of the RDBMS operation out of (i) SELECTION (ii) PROJECTION (iii) UNION (iv) CARTESIAN PRODUCT, which has been used to produce the output as shown in RESULT. Also, find the Degree and Cardinality of the RESULT :

MEMBER

RESULT

Write SQL queries for (i) to (iv) and find outputs for SQL queries (v) to (viii), which are based on the tables.

DVD

MEMBER

1) To display all details from the table MEMBER in descending order of ISSUEDATE

2) To display the DCODE and DTITLE of all Folk Type DVDs from the table DVD.

3) To display the DTYPE and number of DVDs in each DTYPE from the table DVD.

4) To display all NAME and ISSUEDATE of those members from the table. MEMBER who have DVDs issued (i.e., ISSUEDATE) in the year 2017

5) SELECT MIN(ISSUEDATE) FROM MEMBER

6) SELECT DISTINCT DTYPE FROM DVD;

7) SELECT D.DCODE, NAME, DTITLE FROM DVD D, MEMBER M WHERE D.DCODE=M.DCODE;

8) SELECT DTITLE FROM DVD WHERE DTYPE NOT IN ("Folk", "Classical" ) ;

Consider the following DEPT and EMPLOYEE tables. Write SQL queries for (i) to (iv) and find outputs for SQL queries (v) to (viii).

Table: DEPT

Table: EMPLOYEE

Note: DOJ refers to the date of joining ·and DOB refers to the date of Birth of employees

1) To display Eno, Name, Gender from the table EMPLOYEE in ascending order of Eno.

2) To display the Name of all the MALE Employees from the table EMPLOYEE.

3) To display the Eno and Name of those employees from the table EMPLOYEE who are born between '1987-01-01' and '1991-12-01'.

4) To count and display FEMALE employees who have Joined after '1986-01-01'.

5) SELECT COUNT(*), DCODE FROM EMPLOYEE GROUP BY DCODE HAVING COUNT(*)>1;

6) SELECT DISTINCT DEPARTMENT FROM DEPT;

7) SELECT NAME, DEPARTMENT FROM EMPLOYEE E, DEPT D WHERE E.DCODE=D.DCODE AND EN0<1003;

8) SELECT MAX(DOJ), MIN(DOB) FROM EMPLOYEE;

The number of tuples in a relation is called ______.