expression | Execute expressions in a context
kandi X-RAY | expression Summary
kandi X-RAY | expression Summary
Execute expressions in a context
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of expression
expression Key Features
expression Examples and Code Snippets
def _parse_lambda(lam):
"""Returns the AST and source code of given lambda function.
Args:
lam: types.LambdaType, Python function/method/class
Returns:
gast.AST, Text: the parsed AST node; the source code that was parsed to
genera
def regex_find(orig_screen_output, regex, font_attr):
"""Perform regex match in rich text lines.
Produces a new RichTextLines object with font_attr_segs containing highlighted
regex matches.
Example use cases include:
1) search for specif
def preprocess_input_exprs_arg_string(input_exprs_str, safe=True):
"""Parses input arg into dictionary that maps input key to python expression.
Parses input string in the format of 'input_key=' into a
dictionary that maps each input_key to it
Community Discussions
Trending Discussions on expression
QUESTION
I have this code which prints multiple tables
...ANSWER
Answered 2021-Jun-15 at 20:59So, this is a good opportunity to use purrr::map
. You are half way there by applying code to one dataframe.
You can take the code that you have written above and put it into a function.
QUESTION
I have a simple code where I try to define a vector as one of two initializer lists using a ternary operator:
...ANSWER
Answered 2021-Jun-15 at 21:48Because you can't have braces in that context. If you look at cppreference on list initialization, you see that the case inside a ternary operator isn't defined. So it can't be parsed correctly and you get the error you have.
You'd have to use something like this :
QUESTION
I am practicing regular expressions in Kotlin and trying to start with a multiline string. However, I am not receiving any matches. I feel like I am doing it right and can't figure out the problem.
Test lines:
...ANSWER
Answered 2021-Jun-15 at 21:32Here is how it works:
QUESTION
GNU grep's basic (BRE) and extended (ERE) syntax is documented at https://www.gnu.org/software/grep/manual/html_node/Regular-Expressions.html and PCRE is summarized at man pcresyntax
, but there is no explicit comparison. What are the differences between GNU grep's basic/extended and PCRE (-P
) regular expressions?
ANSWER
Answered 2021-Jun-15 at 20:55My research of the major syntax and functionality differences from http://www.greenend.org.uk/rjk/tech/regexp.html:
.
in GNU grep does not match null bytes and newlines (but does match newlines when used with--null-data
), while Perl, everything except\n
is matched.[...]
in GNU grep defines POSIX bracket expressions, while Perl uses "character" classes. I'm not sure on the details. See http://www.greenend.org.uk/rjk/tech/regexp.html#bracketexpression- "In basic regular expressions the meta-characters
?
,+
,{
,|
,(
, and)
lose their special meaning; instead use the backslashed versions\?
,\+
,\{
,\|
,\(
, and\)
." From https://www.gnu.org/software/grep/manual/html_node/Basic-vs-Extended.html. ERE matches PCRE syntax. - GNU grep
\w
and\W
are the same as[[:alnum:]]
and[^[:alnum]]
, while Perl uses alphanumeric and underscore. - GNU grep has
\<
and\>
for start and end of word.
Perl supports much more additional functionality:
- "nongreedy {}" with syntax
re{...}?
- additional anchors and character types
\A
,\C
,\d
,\D
,\G
,\p
,\P
,\s
,\S
,\X
.\Z
,\z
. (?#comment)
- shy grouping
(?:re)
, shy grouping + modifiers(?modifiers:re)
- lookahead and negative lookahead
(?=re)
and(?!re)
, lookbehind and negative lookbehind(?<=p)
and(?
- Atomic groups
(?>re)
- Conditional expression
(?(cond)re)
- ... and more, see
man pcresyntax
QUESTION
I am generating lexical analyzer with JLEX. I found a regular expression for string literal from this link and used it in .jflex file same of other expressions. but it gives me this error :
unterminated string at the end of the line
StringLiteral = \"(\\.|[^"\\])*\"
can anyone help me please, thanks.
...ANSWER
Answered 2021-Jun-15 at 20:46The regular expression you copied is for (f)lex, which uses a slightly different syntax for regular expressions. In particular, (f)lex treats "
as an ordinary character inside bracketed classes, so [^"\\]
is a character class matching anything other than (^
) a quotation mark ("
) or a backslash (\\
).
However, in JFlex, the "
is a quoting character, whether outside or inside brackets. So the "
in the character class is unterminated. Hence the error message.
So you need to backslash-escape it:
QUESTION
I have to parse lists of names, addresses, etc. that were OCRed and have invalid/incorrect characters in them and on the state postal code I need to recognize the pattern with a 2 character state followed by a 5 digit postal code and replace any non numeric characters in the postal code. I might have OK 7-41.03
at the end of a string I need to remove the hyphen and period. I know that re.sub('[^0-9]+', '', '7-41.03')
will remove the desired characters but I need it only replace characters in numbers when found at the end of the string and only if preceded by a two character state wrapped in spaces like OK
. It seems if I add anything to the regular expression as far as a lookbehind expression then I can't seem to get the characters replaced. I've come up with the following but I think there must be a simpler expression to accomplish this. Example:
ANSWER
Answered 2021-Jun-15 at 20:02You need to make use of re.sub
callbacks:
QUESTION
I am using a method to remove univariate outliers. This method only works if the vector contains outliers.
How is it possible to generalize this method to work also with vectors without outliers. I tried with ifelse
without success.
ANSWER
Answered 2021-Jun-15 at 19:58Negate (!
) instead of using -
which would work even when there are no outliers
QUESTION
I get it again and again
...ANSWER
Answered 2021-Jun-15 at 18:09You have to make the property overridable, so make it virtual
:
QUESTION
I have a WPF app, linked to a SQL-server. I am using the MVVM-light package (I do actually have Prism.Core installed, but I'm not sure if I'm using it or not.... new to MVVM).
There's a DataGrid
, bound to an ObservableCollection
.
I have been trying to implement the PropertyChangedEventHandler
, but I can't seem to get it to work.
I have a Delete button bound, and I am able to remove rows, but when I re-open the form, the changes does not carry over.
I tried to change the binding-mode for the DataGrid
from OneWay
to TwoWay
. With OneWay
, the changes does not carry over when I re-open the form. With TwoWay
, I get this error message when opening the child form (which contains the DataGrid
):
System.InvalidOperationException: 'A TwoWay or OneWayToSource binding cannot work on the read->only property 'licenseHolders' of type 'Ridel.Hub.ViewModel.LicenseHoldersViewModel'.'
So, If I then add a set;
to my public ObservableCollection licenseHolders { get; }
,
the program runs, but the previous problem persists, like it did when there was a OneWay
mode configuration on the DataGrid
.
What do I need to do to get this to work without communicating directly with the Sql-server
, which would defy the whole point of using this methodology in the first place?
ANSWER
Answered 2021-Jun-15 at 13:26You are confusing topics. The VM needs InotifyPropertyChanged
events, which you have but are not using, to notify the Xaml in the front-end that a VMs property has changed and to bind to the new data reference.
This is needed for List
s or ObservableCollection
s. Once that is done, the ObservableCollection
will then send notifications on changes to the list as items are added or removed.
Because you miss the first step:
QUESTION
I am using class based projection with constructor expressions. here is a sample code form my work
...ANSWER
Answered 2021-Jun-15 at 00:02try using left join
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install expression
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page