Question

edef extract_num(s, begin, end): Given string s, and "begin" is the index of the first of one or more digits, and "end" is the index one beyond the last digit. Parse out and return the int value of the number, accounting for possible 's' and 'a', Return -1 if the number should be skipped. >>> extract_nun('xx123$, 2, 5) 321 >>> # add Doctests here

Answer 1

Below is the code attached for above question in Python:

#function to extract number from the string.
def extract(s,begin,end):
numbers = [] #empty number list
temp = [] #empty temporary list to store number
for i in range(begin,end): #iterating over string from begin to end
if s[i].isdigit(): #conditional statement to check if element is numeric or not
temp.append(s[i]) #if numeric then adding into temporary list.
else: #if not numeric then
if s[i]=='$': #if element is special character '$' then
#first reversing temp list by temp[::-1])
#then,typecasting list element as string.
#joining list element to form a string
#appended string to numbers list
numbers.append(''.join(map(str,temp[::-1])))
  
elif s[i]!='^':
#if element is '^' we omit it else ,
#typecasting list element as string.
#joining list element to form a string
#appended string to numbers list
numbers.append(''.join(map(str,temp)))
temp = [] #emptying the temp list
#removing all empty element from the numbers list
str_list = list(filter(None, numbers))
#converting every element from string to integer in str_list
for i in range(len(str_list)):
str_list[i] = int(str_list[i])
#returns list
return str_list

#funtion parse_line that parses each line of text file and calls extract to extract numbers
def parse_line(s):
number = extract(s,0,len(s)) #calls extract function
#displays numbers list on console.
print(number)
  
file_name = 'file.txt' #file name

#using with operator to handle file
with open(file_name) as f:
line = f.readline().strip() #reading line and removing any empty spaces at the end.
#reading file's each line.
while(line):
parse_line(line) #calling parse_file function.
line = f.readline().strip()
Refer to the screenshot attached below to better understand the indentation and code:

1 #function to extract number from the string. 2 def extract(s, begin, end): numbers = [] #empty number List temp = [] #empty temporary list to store number for i in range (begin, end): #iterating over string from begin to end if s[i].isdigit(): #conditional statement to check if element is numeric or not temp.append(s[i]) #if numeric then adding into temporary List. else: #if not numeric then if s[i]=='$': #if element is special character '$' then #first reversing temp List by temp[::-1] #then, typecasting List element as string. #joining list element to form a string #appended string to numbers List numbers.append(".join(map(str, temp[::-1]>>> elif s[i]!='X': #if element is 'we omit it else, #typecasting List element as string. #joining List element to form a string #appended string to numbers List numbers.append(".join(map(str, temp))) temp = [] #emptying the temp list #removing all empty element from the numbers List str_list = list(filter (None, numbers)) #converting every element from string to integer in str_List for i in range(len(str_list)): str_list[i] = int(str_list[i]) #returns List return str list

Input File:

31 #funtion parse_line that parses each Line of text file and calls extract to extract numbers 32 def parse_line(s): number = extract(5,0, len(s)) #calls extract function #displays numbers List on console. print(number) 37 file_name = 'file.txt' #file name 38 39 #using with operator to handle file 40 with open(file_name) as f: line = f.readline().strip() #reading Line and removing any empty spaces at the end. #reading file's each line. while(line): 44 parse_line (line) #calling parse_file function. 45 line = f.readline().strip) 43

800!)176^b006$(46$*#63z*16$*06$z5^
455^176$b785$46$##63z*16$*4$z5^
781!)16$*06$z5^(83$*#45z*16$*06$z45^
369!)(36$*#63z*16$*06$z5^176^b0005$
%%##%%##)()&@^#!#

Screenshot of Input File:

file - Notepad - O X File Edit Format View Help 800!) 176^b006$ (46$*#63z*16$*06$25^ 4554176$b785$46$##63z*16$*4$25^ 781!) 16$*06$25^(83$*#45z 16$*06$2454 369!) (36$*#63z*16$*06$25^176460005$ %%##%%##) ()&@^#!# In 5, Col 18 100% Windows (CRLF) UTF-8

Output:

[888,68,64,63,51,68] [671,587,64,63, 61, 4] [781, 61, 8, 8,45, 61.62] [39,63,3,61,68,5eee]

If my answer helps then please upvote ,it means alot
for further queries comment below.

Thank You