i recently started learning flutter and dart, so my apologies if this is a really simple problem, i am trying to generate a list with values from another list, as follows:
List transactions = List.generate(15, (index)=>{
“name”: names[1],
“dp”: “assets/cm1.jpeg”,
});
but i want the numbers 1 to increase by 1 with every new entry. so the list should be outputting the names in my names list 1 by 1 and cm1.jpeg, cm2.jpeg etc. similar to the i+1 code.
Thanks in advance!
You can use the index variable to get the index of the current element you are generating. So first element will run the generate method with an index value of 0, the second will have the value 1 and so on.
With this knowledge you can write something like:
List transactions = List.generate(15, (index)=>{
“name”: names[1 + index],
“dp”: “assets/cm${1 + index}.jpeg”,
});
Related
" Select list item: Attempt to get item number 0, of the list [5]. The minimum valid item number is 1.
Note: You will not see another error reported for 5 seconds. "
Hey Guys,
The message on top appear when the app open the app not crashing but I need to click somewhere on screen few times till it disappear..
The idea is to search a value of var 'UID' in firebase.database and when it found it I need to get the value of is brother key..
I want you please to help me to clear this message I tried a few ways to get the result but nothing yet..
Thanks a lot for helpers :)
When Screen Open.
This is how I tried to get the uid && employeeKey.
for your help me I set var 'UID' = to uid value of employee number 1
'UID' get the value from firebase.auth form on screen 1..
The index in list block returns 0, if the "thing" has not been found in the list and in this case you are trying to get the value from the 0th item from the empKey list, which does not make sense.
Therefore you will have to add an if statement... if the returned index is 0, then do not search for the empKey.
Btw. the better place to ask questions like this would be the MIT App Inventor community...
I have a list that contains sublists. The sequence of the sublist is fixed, as are the number of elements.
schedule = [['date1', 'action1', beginvalue1, endvalue1],
['date2', 'action2', beginvalue2, endvalue2],
...
]
Say, I have a date and I want find what I have to do on that date, meaning I require to find the contents of the entire sublist, given only the date.
I did the following (which works): I created a intermediate list, with all the first values of the sublists. Based on the index i was able to retrieve its entire contents, as follows:
dt = 'date150' # To just have a value to make underlying code more clear
ls_intermediate = [item[0] for item in schedule]
index = ls_intermediate.index(dt)
print(schedule[index])
It works but it just does not seem the Python way to do this. How can I improve this piece of code?
To be complete: there are no double 'date' entries in the list. Every date is unique and appears only once.
Learning Python, and having quite a journey in front of me...
thank you!
I am struggling on creating a formula with Power Bi that would split a single rows value into a list of values that i want.
So I have a column that is called ID and it has values such as:
"ID001122, ID223344" or "IRRELEVANT TEXT ID112233, MORE IRRELEVANT;ID223344 TEXT"
What is important is to save the ID and 6 numbers after it. The first example would turn into a list like this: {"ID001122","ID223344"}. The second example would look exactly the same but it would just parse all the irrelevant text from between.
I was looking for some type of an loop formula where you could use the text find function to find ID starting point and use middle function to extract 8 characters from the start but I had no progress in finding such. I tried making lists from comma separator but I noticed that not all rows had commas to separate IDs.
The end results would be that the original value is on one column next to the list of parsed values which then could be expanded to new rows.
ID Parsed ID
"Random ID123456, Text;ID23456" List {"ID123456","ID23456"}
Any of you have former experience?
Hey I found the answer by myself using a good article similar to my problem.
Here is my solution without any further text parsing which i can do later on.
each let
PosList = Text.PositionOf([ID],"ID",Occurrence.All),
List = List.Transform(PosList, (x) => Text.Middle([ID],x,8))
in List
For example this would result "(ID343137,ID352973) ID358388" into {ID343137,ID352973,ID358388}
Ended up being easier than I thought. Suppose the solution relied again on the lists!
I have a query sequence that I blasted online using NCBIWWW.qblast. In my xml blast file result I obtained for a query sequence a list of hit (i.e: gi|). Each hit or gi| have multiple hsp. I made a dictionary my_dict1 where I placed gi| as key and I appended the bit score as value. So multiple values for each key.
my_dict1 = {
gi|1002819492|: [437.702, 384.47, 380.86, 380.86, 362.83],
gi|675820360| : [2617.97, 2614.37, 122.112],
gi|953764029| : [414.258, 318.66, 122.112, 86.158],
gi|675820410| : [450.653, 388.08, 386.27] }
Then I looked for max value in each key using:
for key, value in my_dict1.items():
max_value = max(value)
And made a second dictionary my_dict2:
my_dict2 = {
gi|1002819492|: 437.702,
gi|675820360| : 2617.97,
gi|953764029| : 414.258,
gi|675820410| : 450.653 }
I want to compare both dictionary. So I can extract the hsp with the highest score bits. I am also including other parameters like query coverage and identity percentage (Not shown here). The finality is to get the best gi| with the highest bit scores, coverage and identity percentage.
I tried many things to compare both dictionary like this :
First code :
matches[]
if my_dict1.keys() not in my_dict2.keys():
matches[hit_id] = bit_score
else:
matches = matches[hit_id], bit_score
Second code:
if hit_id not in matches.keys():
matches[hit_id]= bit_score
else:
matches = matches[hit_id], bit_score
Third code:
intersection = set(set(my_dict1.items()) & set(my_dict2.items()))
Howerver I always end up with 2 types of errors:
1 ) TypeError: list indices must be integers, not unicode
2 ) ... float not iterable...
Please I need some help and guidance. Thank you very much in advance for your time. Best regards.
It's not clear what you're trying to do. What is hit_id? What is bit_score? It looks like your second dict is always going to have the same keys as your first if you're creating it by pulling the max value for each key of the first dict.
You say you're trying to compare them, but don't really state what you're actually trying to do. Find those with values under a certain max? Find those with the highest max?
Your first code doesn't work because I'm assuming you're trying to use a dict key value as an index to matches, which you define as a list. That's probably where your first error is coming from, though you haven't given the lines where the error is actually occurring.
See in-code comments below:
# First off, this needs to be a dict.
matches{}
# This will never happen if you've created these dicts as you stated.
if my_dict1.keys() not in my_dict2.keys():
matches[hit_id] = bit_score # Not clear what bit_score is?
else:
# Also not sure what you're trying to do here. This will assign a tuple
# to matches with whatever the value of matches[hit_id] is and bit_score.
matches = matches[hit_id], bit_score
Regardless, we really need more information and the full code to figure out your actual goal and what's going wrong.
I am trying to just do a basic INSERT operation to a PostgreSQL database through Python via the Psycopg2 module. I have read a great many of the questions already posted regarding this subject as well as the documentation but I seem to have done something uniquely wrong and none of the fixes seem to work for my code.
#API CALL + JSON decoding here
x = 0
for item in ulist:
idValue = list['members'][x]['name']
activeUsers.append(str(idValue))
x += 1
dbShell.executemany("""INSERT INTO slickusers (username) VALUES (%s)""", activeUsers
)
The loop creates a list of strings that looks like this when printed:
['b2ong', 'dune', 'drble', 'drars', 'feman', 'got', 'urbo']
I am just trying to have the code INSERT these strings as 1 row each into the table.
The error specified when running is:
TypeError: not all arguments converted during string formatting
I tried changing the INSERT to:
dbShell.executemany("INSERT INTO slackusers (username) VALUES (%s)", (activeUsers,) )
But that seems like it's merely treating the entire list as a single string as it yields:
psycopg2.DataError: value too long for type character varying(30)
What am I missing?
First in the code you pasted:
x = 0
for item in ulist:
idValue = list['members'][x]['name']
activeUsers.append(str(idValue))
x += 1
Is not the right way to accomplish what you are trying to do.
first list is a reserved word in python and you shouldn't use it as a variable name. I am assuming you meant ulist.
if you really need access to the index of an item in python you can use enumerate:
for x, item in enumerate(ulist):
but, the best way to do what you are trying to do is something like
for item in ulist: # or list['members'] Your example is kinda broken here
activeUsers.append(str(item['name']))
Your first try was:
['b2ong', 'dune', 'drble', 'drars', 'feman', 'got', 'urbo']
Your second attempt was:
(['b2ong', 'dune', 'drble', 'drars', 'feman', 'got', 'urbo'], )
What I think you want is:
[['b2ong'], ['dune'], ['drble'], ['drars'], ['feman'], ['got'], ['urbo']]
You could get this many ways:
dbShell.executemany("INSERT INTO slackusers (username) VALUES (%s)", [ [a] for a in activeUsers] )
or event better:
for item in ulist: # or list['members'] Your example is kinda broken here
activeUsers.append([str(item['name'])])
dbShell.executemany("""INSERT INTO slickusers (username) VALUES (%s)""", activeUsers)