Skip to main content

Python - Mathematical Functions - Hexadecimal, Binary, Exponential, Absolute, Round

🐍 Some mathematical functions are in-built in python. Here are some of them.

Convert Decimal to Hexadecimal

hex(246)
Output:
'0xf6'
hex(512)
Output:
'0x200'

0x is prefix to all hexadecimal numbers in output. The number after 0x is the hexadecimal value.

Convert Decimal to Binary

bin(1234)
Output:
'0b10011010010'

bin(246)
Output:
'0b11110110'
bin(512)
Output:
'0b1000000000'

Exponential Function

pow() function is similar to num1**num2, but it comes useful when you want to execute (num1**num2)%num3. Passing three arguments to pow(), does this.
pow(3,4)
Output:
81
This works just like 3**4
pow(3,4,5)
Output:
1
But this, works equivalent to (3**4)%5. Either of the two ways can be used. At this point I feel (3**4)%5 is better, as anybody reading the code will understand what is being done immediately. While with pow(2,3,4), the person may have to refer to documentation to understand how this function works.

Absolute Value

The function abs() is used to find the absolute value, i.e. it removes the negatives, if any and returns the positive number.
abs(-3.14)
Output:
3.14

abs(3.14)
Output:
3.14

Round

The function round() will round a number to a given precision in decimal digits (default 0 digits). It does not convert integers to floats.
round(295,-1)
Output:
300
round(295,0)
Output:
295
round(295,1)
Output:
295
round(3.1415926535,2)
Output:
3.14

round(3.1415)

Output:
3

Comments

Popular posts from this blog

Difference between .exec() and .execPopulate() in Mongoose?

Here I answer what is the difference between .exec() and .execPopulate() in Mongoose? .exec() is used with a query while .execPopulate() is used with a document Syntax for .exec() is as follows: Model.query() . populate ( 'field' ) . exec () // returns promise . then ( function ( document ) { console . log ( document ); }); Syntax for .execPopulate() is as follows: fetchedDocument . populate ( 'field' ) . execPopulate () // returns promise . then ( function ( document ) { console . log ( document ); }); When working with individual document use .execPopulate(), for model query use .exec(). Both returns a promise. One can do without .exec() or .execPopulate() but then has to pass a callback in populate.

Python - List - Append, Count, Extend, Index, Insert, Pop, Remove, Reverse, Sort

🐍 Advance List List is widely used and it's functionalities are heavily useful. Append Adds one element at the end of the list. Syntax list1.append(value) Input l1 = [1, 2, 3] l1.append(4) l1 Output [1, 2, 3, 4] append can be used to add any datatype in a list. It can even add list inside list. Caution: Append does not return anything. It just appends the list. Count .count(value) counts the number of occurrences of an element in the list. Syntax list1.count(value) Input l1 = [1, 2, 3, 4, 3] l1.count(3) Output 2 It returns 0 if the value is not found in the list. Extend .count(value) counts the number of occurrences of an element in the list. Syntax list1.extend(list) Input l1 = [1, 2, 3] l1.extend([4, 5]) Output [1, 2, 3, 4, 5] If we use append, entire list will be added to the first list like one element. Extend, i nstead of considering a list as one element, it joins the two lists one after other. Append works in the following way. Input l1 = [1, 2, 3] l1.append([4, 5]) Output...

269. Alien Dictionary

  Solution This article assumes you already have some confidence with  graph algorithms , such as  breadth-first search  and  depth-first searching . If you're familiar with those, but not with  topological sort  (the topic tag for this problem), don't panic, as you should still be able to make sense of it. It is one of the many more advanced algorithms that keen programmers tend to "invent" themselves before realizing it's already a widely known and used algorithm. There are a couple of approaches to topological sort;  Kahn's Algorithm  and DFS. A few things to keep in mind: The letters  within a word  don't tell us anything about the relative order. For example, the presence of the word  kitten  in the list does  not  tell us that the letter  k  is before the letter  i . The input can contain words followed by their prefix, for example,  abcd  and then  ab . These cases will never ...