python calculator tutorial

Valuesetdefault (k,v) if K does not exist, set a default value of V, and return V, if K exists, return k corresponding to the Valuekeys () Get all the Keysvalues () Get all the Valuesiteritems () fori,jin D.iteritems ():p rint (i,j) update () M.update (n) m,n are Dictpop (k) Delete k:v corresponding element zip (L1,L2) high-order functions, Dict (Zip (l1,l2)) convert L1 and L2 to Mm=dict (a=1,b=10,c=3 , d=9) printsorted (Mm.iteritems (), key=lambdad:d[1],reverse=true)4. Other common op

This article introduces the Python-based Tkinter implementation of the simple calculator detailed code, share to everyone for your reference, the specific content is as follows The first type: use Python's tkinter to implement a simple calculator #coding: Utf-8from Tkinter import *import timeroot = Tk () def cacl (INPUT_STR): If "x" in Input_str:ret = Input_str

Regular expression is one of the most commonly used in Python development, this article and we share is the Python development using regular expressions to implement the calculator algorithm related content, together look at it, I hope to everyoneLearn Pythonhelpful. (1) Do not use Eval () and other systems to bring the calculation method(2) Implementation of fou

. Embed PHP code in HTML In the front code of the calculator above, we can see that when the data is processed and delivered to the foreground, the data is displayed by writing the PHP code in the P tag. From here we can see how PHP is nested in HTML code. The development here is the PHP code and HTML code nesting, data and page development together, what mode is useless. Summarize The case of the computer contains almost all the previous studies

Run: Actually, python is a very powerful calculator: ^ _ ^, VcD4KPHA + kernel + PC9wPgo8cHJlIGNsYXNzPQ = "brush: java;" >__ author _ = 'job' class ExpStack (): # init method def _ init _ (self ): self. top =-1 self. data = [] # whether Stack is empty def is_empty (self): return-1 = self. top # pop an element from stack def pop (self): if self. is_empty (): print "Stack is Empty... "else: self. dat

Python uses only 40 lines of code to write a calculator instance, and python40 lines This example describes a calculator written in Python with only 40 lines of code. We will share this with you for your reference. The details are as follows: : Code: From tkinter import * reset = Truedef buttonCallBack (event): global

Python + tkinter use 80 lines of code to implement a calculator instance, tkinter80 lines This article describes how to use Python + tkinter to program a simple calculator code example. If you don't talk about it, go straight to the topic. We recommend that you repeat the code and try out the code reuse, use the stri

Python programming uses the tkinter module to implement the complete code example of the calculator software, pythontkinter Python provides libraries for multiple graphic development interfaces. Tkinter is one of them. Tkinter module (Tk Interface) is the interface of Python's standard Tk GUI toolkit. Tk and Tkinter can be used on most Unix platforms, and can als

))expression = "%s%s%s"% (before, ret, after)Print (' After: ', expression)Print ("=" *10, ' previous result is ', "=" *10)# Loop continues the next parenthesis processing operation, this time the carrier is the expression that has been processed, namely:# [' 1-2* ((60-30+-8.0 * (9-2*5/3+7/3*99/4*2998+10*568/14))-( -4*3)/(16-3*2)) ']# so again and again, until the expression no longer contains parenthesesreturn Exec_bracket (expression)# Purpose of using __name__:# The following code executes on

Using regular expressions1, realize subtraction and extension number priority analysis2, the user input 1-2 * ((60-30 + ( -40/5) * (9-2*5/3 + 7/3*99/4*2998 +10 * 568/14))-( -4*3)/(16-3*2)) and other similar formulas, you must parse the inside (), +,-, *, /symbols and formulas (cannot invoke lazy implementations such as eval, etc.), the result of the operation, the result must be consistent with the results of the actual calculator.This is calculated using regular expressions in three steps:1, se

This is the calculator from the web search for small Python projects (original address: http://www.2cto.com/kf/201402/279637.html). However, this code is estimated to be written in Python 2.If you are using a Python version of 3 or more, you need to install pillow yourself. Windows can use the PIP install Pillow on the

Write it in front."""读书的时候上过《设计模式》这一门课，当时使用的教材是程杰老师的《大话设计模式》，使用的语言是C#，学过课程之后初期深感面向对象思想的伟大，但是很少应用到实际开发中。后来我接触了Python，现在工作中用到最多的也是Python，或许是因为Python的便利性，我写的很多脚本/程序都还是面向过程编程，缺少面向对象的思想在里边。因此，我打算重读程杰老师的《大话设计模式》并用Python进行实践。"""

Always have a friend to ask me, listening to my lecture feel can understand, I say the example of writing can also be made, but one to oneself want to copy but write their own time, found that there is no train of thought, do not know how to start. To this I can only say, or because of the practice of less, usually never write code, learn a bit of grammar to be able to get the complex function is not realistic, learning language is a progressive process, not after tens of thousands of lines of c

Introduction In this article, I will show you how to parse and calculate a four arithmetic expression just like a general calculator. When we end, we will get a calculator that can process expressions such as 1 + 2 *-(-3 + 2)/5.6 + 3. Of course, you can also expand it more powerful. I wanted to provide a simple and interesting course to explain the syntax analysis and regular syntax compilation principles )

Brief introduction In this article, I'm going to show you how to parse and compute a arithmetic expression like a general-purpose calculator. When we're done, we'll get a calculator that can handle expressions such as 1+2*-( -3+2)/5.6+3 style. Of course, you can also expand it to be more powerful. My intention is to provide a simple and interesting course to explain grammar analysis and formal grammar (com

()) # Get the text This string format self.list1.append (Self.val.get ()) # Appends text to List1, where Val.get is the list of contents in the text Self.list1.append (a Ddnum) # "2 +" Print (SELF.LIST1) # need to determine if the operation symbol is pressed Self.val0.set (self.list1) self.operation_s IGN = True self.sign1 = False #等号操作 def eq_operation (self): try:if self.sign2 = = true: If Self.sign1 = = true: #sign1 to True can be equal to Self.list1.append (Self.val.get ()) #

(i)elifFIND_[INDEX-1] = ="-": #If two negative numbers are subtracted, they are added or subtracted ifTag = =True:res+=float (i)Else: Res-=float (i)Else: #case where I is empty when processing without parentheses ifI! ="": Res=float (i)returnResif __name__=='__main__': whileTrue:calc_input= Input ("Please enter a calculation formula \ n default to:%s:"%a). Strip ()Try: ifLen (calc_input) = =0:calc_input=a calc_input= R'%s'%calc_input#do special treatment t

.]*] \) ', S_MATCH_STR). Group (1) s = S.replace (S_match_str, S_match_str_match) print (s) Else:print ("Call processing%s"%s_match_str) S_match_str_str=re.search (' \ ([+\-*/0-9.] *) \) ', s). Group (1)Ret=handler_expression (s_match_str_str) s = s.replace (S_match_str, str (ret)) print (s) Else:flag=false return s# no_braces_result=hadler_braces (' ( -1+ (2-5* ( -1)) * (2-5)) # Result=handler_expressi On (no_braces_result) # print (result) if __name__ = = ' __main__ ': While tru

python--completes a small program through a while, for, If-else On the third day of learning Python, Mr. Zheng Let us write a calculation of the fare of the small program, fortunately before there is a small program to write the basis, and then soon completed, the following is related to the content (^_^) ∠※ topic Requirements: according to the following information, please help Xiao Ming calculate the tot

relatively simple logic flow, the reader can also think of there is no better, more reasonable wording. But at least so far, no problem has been identified.?To this part at least our entire program structure has been more complete, less than the previous version of the main program 50 lines, while the reader can easily find that the changes will be more convenient than before (a method, change the whole), in the following section, we continue to optimize?For more instructional videos and downlo