Graphs are not diplayed with python 3. --> modules/log/endpoints.py requires change in line 59:
'''
import csv

    array = []

    with open(filename, 'rt', encoding='utf-8') as f:

        reader = csv.reader(f)

'''

charts fixed df8c6a7

Graphs are not diplayed with python 3. --> modules/log/endpoints.py requires change in line 59:
'''
import csv

    array = []

    with open(filename, 'rt', encoding='utf-8') as f:

        reader = csv.reader(f)

'''

I have added some code to display only one point per minute.
Now loads ok a 5 days fermentation graph.

import csv
        array = []
        with open(filename, 'rb') as f:
            reader = csv.reader(f)
            l_time=0
            for row in reader:
                try:
                    p_time=int((datetime.datetime.strptime(row[0], "%Y-%m-%d %H:%M:%S") - datetime.datetime(1970, 1, 1)).total_seconds()) * 1000
                    if ( abs(float(row[1])) < 100 ) and ( p_time >= l_time ):
                        l_time = p_time + 60000;
                        array.append([p_time , float(row[1])])
                except:
                    pass
        return array

Also on lines 80 and 121 of Modules/core/controler.py added tank name in the bottom of the graph.

 80         result.append({"name": kettle.name+" Temp", "data_type": "sensor", "data_id": kettle.sensor})

121              result.append({"name": fermenter.name+" Temp", "data_type": "sensor", "data_id": fermenter.senso
r})

fermenter.py causes an error:
File "/home/pi/craftbeerpi3/modules/fermenter/init.py", line 187, in start_fermentation
inactive.direction = "C" if current_temp >= inactive.temp else "H"
TypeError: '>=' not supported between instances of 'float' and 'str'

-> fix:
inactive.direction = "C" if float(current_temp) >= float(inactive.temp) else "H"

fermenter.py causes an error:
File "/home/pi/craftbeerpi3/modules/fermenter/init.py", line 187, in start_fermentation
inactive.direction = "C" if current_temp >= inactive.temp else "H"
TypeError: '>=' not supported between instances of 'float' and 'str'

-> fix:
inactive.direction = "C" if float(current_temp) >= float(inactive.temp) else "H"

I use cbpi only to brew, I ferment with brewpiless, but I'll try to fix this...

I have added some code to display only one point per minute.
Now loads ok a 5 days fermentation graph.

import csv
        array = []
        with open(filename, 'rb') as f:
            reader = csv.reader(f)
            l_time=0
            for row in reader:
                try:
                    p_time=int((datetime.datetime.strptime(row[0], "%Y-%m-%d %H:%M:%S") - datetime.datetime(1970, 1, 1)).total_seconds()) * 1000
                    if ( abs(float(row[1])) < 100 ) and ( p_time >= l_time ):
                        l_time = p_time + 60000;
                        array.append([p_time , float(row[1])])
                except:
                    pass
        return array

Also on lines 80 and 121 of Modules/core/controler.py added tank name in the bottom of the graph.

 80         result.append({"name": kettle.name+" Temp", "data_type": "sensor", "data_id": kettle.sensor})

121              result.append({"name": fermenter.name+" Temp", "data_type": "sensor", "data_id": fermenter.senso
r})

could you create a PR against my branch? or maybe send me a patch...

I use cbpi only to brew, I ferment with brewpiless, but I'll try to fix this...

ok, i changed the code yesterday to the line i posted and the error was gone