nested

问题 I’m looking for a way to convert a dataframe into a dictionary, very similar to what has been asked here: Convert pandas DataFrame to a nested dict Assuming a sample data frame name v1 v2 v3 0 A A1 A11 1 1 A A2 A12 2 2 B B1 B12 3 3 C C1 C11 4 4 A A2 A21 6 5 A A2 A21 8 The number of columns may differ and so does the column names. I’m looking to generate : { 'A' : { 'A1' : { 'A11' : 1 }, 'A2' : { 'A12' : 2 , 'A21' : 6 , 'A21' : 8 }, 'B1' : {}, 'C1' : {} }, 'B' : { 'A1' : {}, 'A2' : {}, 'B1' :

问题 I've had a look at various rbinding list questions such as this but I can't really find a more efficient way of doing this. I have a nested list nestlist that contains three lists which each contain two dataframes: df1 <- data.frame(ID = paste0(LETTERS[1:4],1:4), valueA = seq(0.1,0.4,0.1), Category= "Apples") df2 <- data.frame(ID = paste0(LETTERS[1:4],1:4), valueB = seq(0.1,0.4,0.1), Category= "Apples") list1 <- list(df1,df2) df3 <- data.frame(ID = paste0(LETTERS[1:4],1:4), valueA = seq(0.1,0

问题 With the Python (2.7) ternary expression x if cond else y what is the logical order when evaluating multiple expressions of these nested in order: e.g. 1 if A else 2 if B else 3 Drawing out the truth table for this is appears this is evaluated as 1 if A else (2 if B else 3) rather than (1 if A else 2) if B else 3 : A True False B True 1 2 False 1 3 Could someone please explain why this is executed in this order, and possibly suggest some material that gives an intuition about why this is used

问题 I was trying to shorten the code for this problem when I encountered the problem. Basically, I was trying a nested dictionary comprehension & was unsuccessful in the attempt. Here is what I tried. dict2 = {key:value for key, value in line.split(":") for line in ["1:One", "2:Two", "4:Four"]} print dict2 When I run this, it gives me NameError: name 'line' is not defined And, when I reverse the for statements like this dict2 = {key:value for line in ["1:One", "2:Two", "4:Four"] for key, value in

问题 I was trying to shorten the code for this problem when I encountered the problem. Basically, I was trying a nested dictionary comprehension & was unsuccessful in the attempt. Here is what I tried. dict2 = {key:value for key, value in line.split(":") for line in ["1:One", "2:Two", "4:Four"]} print dict2 When I run this, it gives me NameError: name 'line' is not defined And, when I reverse the for statements like this dict2 = {key:value for line in ["1:One", "2:Two", "4:Four"] for key, value in

问题 I have this list: list1 = [['X1',2],['X2',4],['Y1',2],['Y2',4]] and I want to create this dict: dict1 = {'X': {'1':2},{'2':4},'Y':{'1':2},{'2':4}} so that I can use dict1['X']['1'] and this outputs '2' Can someone help me out? I've tried multiple approaches but without any success. 回答1: You can use collections.defaultdict : >>> from collections import defaultdict >>> list1 = [['X1',2],['X2',4],['Y1',2],['Y2',4]] >>> d = defaultdict(dict) >>> for (c,i), n in list1: ... d[c][i] = n ... >>> d

问题 I am trying to write a predicate that ‘exists’ inside the ‘scope’ of another predicate . The reason I need this is because both predicates make use of the same very large parameters/arrays and the predicate I want to nest is doing self recurssion many times , so I want to avoid copying the same parameters . So , is there any way i can do this in Swi-Prolg ? Thanks in advance . 回答1: You don't need to. You have to realize that all the terms "named" by Prolog variable names are already global ,

问题 I have this strange issue, keyboard keeps closing while typing when TextInput is placed inside Child Functional Component. This issue does not exist if TextInput is placed directly under Parent Component. Here is my code const SignInScreenC = props => { // define Hook states here const [email, setEmail] = useState(""); const [password, setPassword] = useState(""); const [isEmailEmpty,setIsEmailEmpty] = useState(false); const [isEmailValid,setIsEmailValid] = useState(true); const

问题 I have this strange issue, keyboard keeps closing while typing when TextInput is placed inside Child Functional Component. This issue does not exist if TextInput is placed directly under Parent Component. Here is my code const SignInScreenC = props => { // define Hook states here const [email, setEmail] = useState(""); const [password, setPassword] = useState(""); const [isEmailEmpty,setIsEmailEmpty] = useState(false); const [isEmailValid,setIsEmailValid] = useState(true); const

问题 Looking for a generic solution where I can remove the specific key and its value from dict. For example, if dict contains the following nested key-value pair: data={ "set": { "type": "object", #<-- should remove this key:value pair "properties": { "action": { "type": "string", #<-- should NOT remove this key:value pair "description": "My settings" }, "settings": { "type": "object", #<-- should remove this key:value pair "description": "for settings", "properties": { "temperature": { "type":