concatenation

问题 I have a task where I need to concatenate 2 pathnames: absolute + relative in perl. The following describes what I am trying to achieve: dir1/dir2/dir3/ + ../filename => dir1/dir2/filename dir1/dir2/dir3/ + ../../filename => dir1/filename I have only solution that counts ".." in relative path, say X, then splits the absolute path into dirs and count them - Y and finally concatenates only Y-X dirs with filename. This seems too bulky and I wonder whether better solution exists (I am sure it

问题 Looking to clean up a .txt file from NMEA GPS. My current code is below. deletes = ['$GPGGA', '$GPGSA', '$GPGSV', '$PSRF156', ] searchquery = '$GPRMC' with open('Drive_home.txt_rf') as f1: with open('Drive_home_1.txt', 'w+') as f2: lines = f1.readlines() for i, line in enumerate(lines): if line.startswith(searchquery): if not any(delete in lines[i + 1] for delete in deletes): f2.write(line) f2.write(lines[i + 1]) Which outputs one txt. and looks like... $GPRMC 204249 A 3504.5449 N 8509.0603 W

问题 I'd appreciate any assistance people could provide with this one. I've tried to follow a couple of other posts (GROUP BY to combine/concat a column), but when I do this, it combines everything. I have a table in SQL that holds contact data. Some contacts in the database have the same email address, particularly admin@, accounts@, etc. We also have a list of contact preferences for each contact: Emergency Contact, Accounts, WHS, etc. I'm trying to select the results of the table, but only one

问题 Is it possible to select the concatenation of all the results returned by a subquery? So if the subquery returns more than one row, I can somehow get all the results contained in a single string? 回答1: Sort of. What you can get is the concatenated result of all the rows that were grouped together using GROUP_CONCAT. You could use that to employ GROUP BY by a column that you know would group the result set correctly and then using the function to return the concated groups. The manual page

问题 I need to concatenate two strings that are in different lists and check if the output string is in a dictionary. The code I've tried is: x=['casa','lo','pre','computer'] y=['music','sun','ve','sident','house'] dic=['sunday','love','president','house','computer'] text=[] errors=[] iter_y=iter(y) iter_x=iter(x) for i in iter_x: if i in dic: text.append(i) else: try: concatenated= i + next(iter_y) if concatenated in dic: text.append(concatenated) except StopIteration: continue else: errors

问题 I have input array: np.random.seed(45) a = np.random.randint(100,size=(5,21)) print (a) [[75 30 3 32 95 61 85 35 68 15 65 14 53 57 72 87 46 8 53 12 34] [24 12 17 68 30 56 14 36 31 86 36 57 61 79 17 6 42 11 8 49 77] [75 63 42 54 16 24 95 63 98 22 27 32 16 75 58 60 54 96 70 32 16] [59 92 55 88 5 81 93 79 67 55 60 57 83 27 78 18 87 55 20 9 9] [73 27 57 50 7 57 78 68 23 75 41 39 70 2 71 70 27 47 54 93 19]] Array of indices: b = np.array( [[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [9, 8, 7, 6, 5, 4, 3, 2, 1

问题 I'm trying to use X macros and preprocessor concatenation, both for the first time, together. I've read a lot of the other questions on SO related to preprocessor concatenation but not yet been able to wrap my head around them or how to adapt those to my use case. The list of items is a list of ID numbers for a bunch of structs , like so: #define LIST_OF_ID_NUMS \ X(1) \ X(2) \ X(3) \ X(4) \ X(5) \ X(6) \ X(7) \ X(8) \ X(9) \ X(10) \ X(11) I can declare the structs like so: #define X(id_num)

问题 I have two relations such as relation1 and relation2. relation1 has columns of A,B,C and relation2 has columns of D,E,F. I want to add A of relation1 with D of relation2 where C = F. For the C values which do not exist in relation2 must appear and F values which do not appear in relation1 also must appear How to do this postgresql? 回答1: Use a FULL [OUTER] JOIN to include rows from either side without a matching row on the other side: SELECT COALESCE(r1.a, 0) + COALESCE(r2.d, 0) AS a_d FROM

问题 How can I concat two fields and text in between? I've tried all of the following and nothing has worked... ([fldCode1] || ':' ||[fldCode2]) AS Method ([fldCode1] + ':' + [fldCode2]) AS Method ([fldCode1] & ':' & [fldCode2]) AS Method *** & cannot be used with varchar 回答1: This should work select [fldCode1] + ':' + [fldCode2] from tab or if the columns are numeric select cast([fldCode1] as varchar(100)) + ':' + cast([fldCode2] as varchar(100)) from tab 回答2: The first and last forms are not

问题 I'm trying to concatenate two dataframes, which look like that: df1: +---+---+ | a| b| +---+---+ | a| b| | 1| 2| +---+---+ only showing top 2 rows df2: +---+---+ | c| d| +---+---+ | c| d| | 7| 8| +---+---+ only showing top 2 rows They both have the same number of rows, and I would like to do something like: +---+---+---+---+ | a| b| c| d| +---+---+---+---+ | a| b| c| d| | 1| 2| 7| 8| +---+---+---+---+ I tried: df1=df1.withColumn('c', df2.c).collect() df1=df1.withColumn('d', df2.d).collect()