Merge pull request geekcomputers#629 from ishitagupta8720/master

added comments

Author: geekcomputers

Binary_search.py

@@ -3,19 +3,19 @@
 def binarySearch(arr, l, r, x):
     while l <= r:
 
-        mid = l + (r - l) / 2;
+        mid = l + (r - l) / 2; #extracting the middle element of the array
 
         # Check if x is present at mid 
         if arr[mid] == x:
             return mid
 
             # If x is greater, ignore left half
         elif arr[mid] < x:
-            l = mid + 1
+            l = mid + 1 #l is initialised to the rightmost element of the middle so that the search could be started from there the next time
 
         # If x is smaller, ignore right half 
         else:
-            r = mid - 1
+            r = mid - 1 #r is initialised to the leftmost element of the middle so that the search goes till there only the next time
 
     # If we reach here, then the element was not present 
     return -1
@@ -25,12 +25,14 @@ def binarySearch(arr, l, r, x):
 if __name__ == "__main__":
     # User input array
     print("Enter the array with comma separated in which element will be searched")
-    arr = map(int, input().split(","))
+    arr = map(int, input().split(",")) #the input array will of int type with each element seperated with a comma due to the split fucntion
+                                       #map function returns a list of results after applying the given function to each item
     x = int(input("Enter the element you want to search in given array"))
 
     # Function call
     result = binarySearch(arr, 0, len(arr) - 1, x)
-
+     
+    #printing the output
     if result != -1:
         print("Element is present at index {}".format(result))
     else:

CountMillionCharacter.py

@@ -8,7 +8,8 @@
 """
 import re
 
-pattern = re.compile("\W")
+pattern = re.compile("\W") #re is used to compile the expression more than once
+#wordstring consisting of a million characters
 wordstring = '''SCENE I. Yorkshire. Gaultree Forest.
 Enter the ARCHBISHOP OF YORK, MOWBRAY, LORD HASTINGS, and others
 ARCHBISHOP OF YORK
@@ -293,17 +294,17 @@
 Before, and greet his grace: my lord, we come.
 Exeunt'''
 
-wordlist = wordstring.split()
+wordlist = wordstring.split() #splits each word with a space
 
 for x, y in enumerate(wordlist):
-    special_character = pattern.search(y[-1:])
+    special_character = pattern.search(y[-1:]) #searches for a pattern in the string
     try:
-        if special_character.group():
+        if special_character.group():  #returns all matching groups
             wordlist[x] = y[:-1]
     except:
         continue
 
-wordfreq = [wordlist.count(w) for w in wordlist]
+wordfreq = [wordlist.count(w) for w in wordlist]  #counts frequency of a letter in the list
 
 print("String\n {} \n".format(wordstring))
 print("List\n {} \n".format(str(wordlist)))

Day_of_week.py

@@ -1,14 +1,14 @@
 # Python program to Find day of 
 # the week for a given date 
-import calendar
-import datetime
+import calendar  #module of python to provide useful fucntions related to calendar
+import datetime # module of python to get the date and time 
 
 
 def findDay(date):
-    born = datetime.datetime.strptime(date, '%d %m %Y').weekday()
-    return (calendar.day_name[born])
+    born = datetime.datetime.strptime(date, '%d %m %Y').weekday() #this statement returns an integer corresponding to the day of the week
+    return (calendar.day_name[born]) #this statement returns the corresponding day name to the integer generated in the previous statement
 
 
 # Driver program 
-date = '03 02 2019'
-print(findDay(date))
+date = '03 02 2019' #this is the input date
+print(findDay(date))  # here we print the final output after calling the fucntion findday