ValueError: could not convert string to float

YassineKira

Hello everyone, hope you are all well :). First i search in my database, i change the tuple into a list then i want change a list of string to a list of foat so i can manipulate the value.

I make the type in database in string i dont know if i have to change it, tell me ?

I dont know what is wrong, thanks in advance

the lists :

[('78,38',), ('100,40745',), ('90,75',), ('110,32',), ('89,6',)]
['78,38', '100,40745', '90,75', '110,32', '89,6']

the error :

ValueError: could not convert string to float: '78,38'

            searchrol = "Isolation Thermique par l'Extérieur"
            cursor = db.cursor()
            result_5 = cursor.execute("SELECT prix FROM PU WHERE desig_pu= ?  ", (str(searchrol),))
            row_5 = result_5.fetchall()
            print(row_5)
            liste = []
            my_list = [] 
            for tupl in row_5: # initialisation de liste
                for i in tupl: 
                    liste.append(i)  
            print (liste) # afficher la liste
            my_list = [float(i) for i in liste]
            #my_list = list(map(float, liste))
            #print(type(liste[0]))
            print (my_list)
            BT = 113.2
            BT0 = 113.4
            row_actualise = []
            for x in liste:
                y = x*(BT/BT0)
                row_actualise.append(str(y))
            print(row_actualise)
![Capture.PNG](https://ddgobkiprc33d.cloudfront.net/98bca980-012f-474c-a7a5-6d98ccc93e80.PNG) ![Capture1.PNG](https://ddgobkiprc33d.cloudfront.net/573582f4-7e1d-412b-ab7a-cf6cc2f0e590.PNG)

KroMignon

@YassineKira This has nothing to do with Qt, this is a Python script issue

jsulm

@YassineKira said in ValueError: could not convert string to float:

ValueError: could not convert string to float: '78,38'

You know that floating point numbers in Python (and all other programming languages I know) use a dot instead of a colon?!
So, 78,38 is NOT a floating POINT number! 78.38 is a floating point number. You should learn the basic stuff first...

YassineKira

@KroMignon Well, i try to learn from anothers in every forum, sorry :), @jsulm Thank you Sir, you are a Life saver :)