 
 
# Constructor to initialize the class variables def init (self, capacity): self.top = -1 self.capacity = capacity # This array is used a stack self.array = [] # Precedence setting self.output = [] self.precedence = {'+':1, '-':1, '*':2, '/':2, '^':3} 
 
 
# check if the stack is empty def isEmpty(self): return True if self.top == -1 else False 
 
# Return the value of the top of the stack def peek(self): return self.array[-1] 
 
# Pop the element from the stack def pop(self): if not self.isEmpty(): self.top -= 1 return self.array.pop() else: return "$" 
 
# Push the element to the stack def push(self, op): self.top += 1 self.array.append(op) 
 
# A utility function to check is the given character # is operand def isOperand(self, ch): return ch.isalpha() 
 
# Check if the precedence of operator is strictly # less than top of stack or not def notGreater(self, i): try: a = self.precedence[i] b = self.precedence[self.peek()] return True if a <= b else False except KeyError: return False 
 
# The main function that converts given infix expression # to postfix expression def infixToPostfix(self, exp): 
 
# Iterate over the expression for conversion for i in exp: # If the character is an operand, # add it to output if self.isOperand(i): self.output.append(i) 
 
# If the character is an '(', push it to stack elif i == '(': self.push(i) 
 
# If the scanned character is an ')', pop and # output from the stack until and '(' is found elif i == ')': while( (not self.isEmpty()) and self.peek() != '('): a = self.pop() self.output.append(a) if (not self.isEmpty() and self.peek() != '('): return -1 

else: self.pop() 
 
# An operator is encountered else: while(not self.isEmpty() and self.notGreater(i)): self.output.append(self.pop()) self.push(i) 
 
# pop all the operator from the stack while not self.isEmpty(): self.output.append(self.pop()) 
 
result= "".join(self.output) print(result) # Driver program to test above function exp = "a+b*(c^d-e)^(f+g*h)-i" obj = Conversion(len(exp)) obj.infixToPostfix(exp)

created 5 years ago

Python Online Compiler

Write, Run & Share Python code online using OneCompiler's Python online compiler for free. It's one of the robust, feature-rich online compilers for python language, supporting both the versions which are Python 3 and Python 2.7. Getting started with the OneCompiler's Python editor is easy and fast. The editor shows sample boilerplate code when you choose language as Python or Python2 and start coding.

Taking inputs (stdin)

OneCompiler's python online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample python program which takes name as input and print your name with hello.

import sys
name = sys.stdin.readline()
print("Hello "+ name)

About Python

Python is a very popular general-purpose programming language which was created by Guido van Rossum, and released in 1991. It is very popular for web development and you can build almost anything like mobile apps, web apps, tools, data analytics, machine learning etc. It is designed to be simple and easy like english language. It's is highly productive and efficient making it a very popular language.

Tutorial & Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition IF-ELSE is used.

if conditional-expression
    #code
elif conditional-expression
    #code
else:
    #code

Note:

Indentation is very important in Python, make sure the indentation is followed correctly

2. For:

For loop is used to iterate over arrays(list, tuple, set, dictionary) or strings.

Example:

mylist=("Iphone","Pixel","Samsung")
for i in mylist:
    print(i)

3. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while condition  
    #code

Collections

There are four types of collections in Python.

1. List:

List is a collection which is ordered and can be changed. Lists are specified in square brackets.

Example:

mylist=["iPhone","Pixel","Samsung"]
print(mylist)

2. Tuple:

Tuple is a collection which is ordered and can not be changed. Tuples are specified in round brackets.

Example:

myTuple=("iPhone","Pixel","Samsung")
print(myTuple)

Below throws an error if you assign another value to tuple again.

myTuple=("iPhone","Pixel","Samsung")
print(myTuple)
myTuple[1]="onePlus"
print(myTuple)

3. Set:

Set is a collection which is unordered and unindexed. Sets are specified in curly brackets.

Example:

myset = {"iPhone","Pixel","Samsung"}
print(myset)

4. Dictionary:

Dictionary is a collection of key value pairs which is unordered, can be changed, and indexed. They are written in curly brackets with key - value pairs.

Example:

mydict = {
    "brand" :"iPhone",
    "model": "iPhone 11"
}
print(mydict)

Supported Libraries

Following are the libraries supported by OneCompiler's Python compiler

Name	Description
NumPy	NumPy python library helps users to work on arrays with ease
SciPy	SciPy is a scientific computation library which depends on NumPy for convenient and fast N-dimensional array manipulation
SKLearn/Scikit-learn	Scikit-learn or Scikit-learn is the most useful library for machine learning in Python
Pandas	Pandas is the most efficient Python library for data manipulation and analysis
DOcplex	DOcplex is IBM Decision Optimization CPLEX Modeling for Python, is a library composed of Mathematical Programming Modeling and Constraint Programming Modeling