Chapter 13: Python

Question 1

Declaration of variables

Answer 1

• No declaration necessary
• A comment should be used either way

#Number1: Type INTEGER
#YourName: Type STRING

Question 2

Assignment of constants

Answer 2

• identifier=value

* PI=3.14

Question 3

Assignment of variables

Answer 3

•identifier=expressions

• A=34
• B=B+1

Question 4

Arithmetic operations

Answer 4

• • | - | * | / | ** | // | %

* Rules of precedence should be followed

Question 5

Outputting information

Answer 5

• print(printlist)

* print(“Hello, ”,YourName,”Your number is: “,Number1)

Question 6

Comments

Answer 6

This is a comment

Question 7

Data types

Answer 7

• int
• float
• str
• bool
• datetime

Question 8

Boolean expressions

Answer 8

• ==
• !=
• >
• <
• > =
• <=
• and | or | not
• in

Question 9

Selection statements

Answer 9

if x<0:
  print(“Negative”)
elif x=0:
  print(“Zero”)
else:
  print(“Positive”)

Question 10

Count-controlled loops

Answer 10

for x in range (5):

print(x)

Question 11

Pre-condition loops

Answer 11

Answer=‘ ‘

while Answer != “Y”:
Answer=input(“Enter Y or N”)

Question 12

Creating 1D arrays

Answer 12

•List1=[]
  List1.append(“Fred”)
  List1.append(“Jack”)
  List1.append(“Ali”)
•List2=[0,0,0,0,0,0,0]
•List3=[0 for i in range (100)]
•List4=[“ “]*100

Question 13

Accessing 1D arrays

Answer 13

• NList[24]=0

* AList[3]=“D”

Question 14

Creating 2D arrays

Answer 14

•Board=[0 for i in range(7)]
for j in range(6)

•Board=[07]6

Question 15

Accessing 2D arrays

Answer 15

Board [2][3]=0

Question 16

String manipulation built-in functions

Answer 16

• ThisString[P]
• chr(i)
• ord(ch)
• len(s)
• s=s1+s2

Question 17

Slicing

Answer 17

• ThisString[2:]: CDEFG
• ThisString[:2]: AB
• ThisString[-2:]: FG
• ThisString[:-2]: ABCDE

Question 18

Truncating numbers

Answer 18

int(x)

Question 19

String —> integer

Answer 19

int(s)

Question 20

String —> float

Answer 20

float(x)

Question 21

Random number generator

Answer 21

randint(1,6)

Question 22

Date and time

Answer 22

from datetime import * SomeDate=date(2015,3,15)

Today=date.today
print(SomeDate)
print(Today)
SomeDate=SomeDate+TimeDelat(1)

Question 23

Writing on a text file

Answer 23

FileHandle=open(“Text.txt”,”w”)
FileHandle.write(LineOfText)
FileHandle.close()

Question 24

Reading from a text file

Answer 24

FileHandle=open(“Text.txt”,”r”)
LineOfText=FileHandle.readline()
FileHandle.close

Question 25

Appending to a text file

Answer 25

FileHandle=open(“Text.txt”,”a”)
FileHandle.write(LineOfText)
FileHandle.close()

Question 26

EoF marker

Answer 26

FileHandle=open(“Text.txt”,”r”)
LineOfText=FileHandle.readline()
while len(LineOfText)>0:
  LineOfText=FileHandle.readline()
  print(LineOfText)
FileHandle.close()