I am reading a line from a text file. It contains the date in YYYY-MM-DD format. I am trying to convert it to datetime object so as to find the difference between two dates.
l = datetime.strptime(last_execution_date,"%Y-%m-%d").date()
Its throwing an error:ValueError: unconverted data remains:
But when I am using below its working perfectly fine
l = datetime.strptime('2019-01-25',"%Y-%m-%d").date()
My complete code looks something like this:
def incoming_mails_duration():
f = open('last_script_execution_time.txt', 'r')
last_execution_date = f.readline()
print(last_execution_date)
print(type(last_execution_date))
l = datetime.strptime(last_execution_date,"%Y-%m-%d").date()
print(l)
print(type(l))
present_date = date.today()
delta_days = abs((present_date - l).days)
f.close()
Why I am getting the above error when I am passing the string as variable read from a file ?
It is because f.readline() returns string with \n in the end. You either have to strip the newline character or include it inside strptime format argument.
Solution 1:
last_execution_date = f.readline().strip()
Solution 2:
l = datetime.strptime(last_execution_date,"%Y-%m-%d\n").date() # Note \n
Note
Also it is good practice to open files with with statement. This is a safe way to handle files. File will be safely closed even if exception occurred inside with block.
with open(filepath) as f:
for line in f:
# Work with line here
pass
Related
I am trying to evaluate strings within a for loop within an R script using JuliaCall::julia_eval. While I was able to accomplish this in R using the deSolve package, I am running into issues when converting the code to one that is compatible with Julia. The base code for the correctly functioning R deSolve code is shown below.
library(deSolve)
library(dplyr)
Combine <- c(" - 1*0.4545*(H2O2^1) - 1*27000000*(`$OH`^1)*(H2O2^1)", " - 1*3100000000*(`1,4-dioxane`^1)*(`$OH`^1)",
" - 1*33000*(TOC^1)*(`$OH`^1)", "2*0.4545*(H2O2^1) - 1*3100000000*(`1,4-dioxane`^1)*(`$OH`^1) - 1*33000*(TOC^1)*(`$OH`^1) - 1*27000000*(`$OH`^1)*(H2O2^1) - 1*8500000*(`$OH`^1)*(`HCO3-`^1) - 1*390000000*(`$OH`^1)*(`CO3 2-`^1)",
" - 1*8500000*(`$OH`^1)*(`HCO3-`^1)", " - 1*390000000*(`$OH`^1)*(`CO3 2-`^1)"
)
time <- seq(from=0, to=0.01, by = 1E-4)
State <- c(H2O2 = 0.000294117647058824, `1,4-dioxane` = 0.00000113494,
TOC = 0, `$OH` = 0, `HCO3-` = 0.003766104, `CO3 2-` = 0.0000167638711956647)
ODEcreater2 <- function(t, state, parameters){
with(as.list(c(state)),{
for (i in 1:6) { #
dY[i] <- eval(parse(text=Combine[i]))}
return(list(dY))
} )}
out1<- ode(y = state, times = time, func = ODEcreater2, parms = NULL)
I am trying to use replicate the code and run it in Julia to improve the speed of the ODE solver by using diffeqr vs. deSolve. Unfortunately, I am running into evaluating the string/expression within a for loop in julia_call.
library(diffeqr)
diffeqr::diffeq_setup()
library(JuliaCall)
julia <- julia_setup()
ODEcreater <- JuliaCall::julia_eval("
function (dY,t,state)
for i in 1:6
dY[i] = eval(Meta.parse(:Combine[i]))
end
end")
tspan <- list(1E-6, 1E-3)
sol = diffeqr::ode.solve(ODEcreater,state,tspan, abstol=1e-8, reltol=1e-8)
Does anyone have any insight into the best way to evaluate the strings within the for loop? I have been investigating metaexpressions on the JuliaLang website but am still lost.
As mentioned in the duplicate question https://stackoverflow.com/a/58766919/1544203 , building the string and then doing
sprintf("function f(du,u,p,t)\n%s\nend", paste(Combine, collapse="\n"))
from the R side builds a single string which matches the format that works. This is also optimal since it excludes any extra function calls from the generated function.
from julia docs:
parse(str; raise=true, depwarn=true)
Parse the expression string greedily, returning a single expression. An error is thrown if there are additional
characters after the first expression. If raise is true (default), syntax errors will raise an error; otherwise, parse
will return an expression that will raise an error upon evaluation. If depwarn is false, deprecation warnings will be
suppressed.
julia> Meta.parse("x = 3")
:(x = 3)
so, Meta.parse accepts a string and returns an expression. this should evaluate correctly:
eval(Meta.parse(Combine[i]))
one problem i see is the use of non-valid julia variable names, like $OH
I have a RegexMatch object which I'd like to convert into a string:
mm = match(r"(?<=Info: ).+", "Info: Kim")
However, I can't figure out how to convert it into a string. The following does not work:
String(mm)
convert(String, mm)
How is this supposed to be accomplished?
You can also use capturing group and index:
julia> mm = match(r"((?<=Info: ).+)", "Info: Kim")
RegexMatch("Kim", 1="Kim")
julia> mm[1]
"Kim"
The field .match will convert the match object into a string.
mm.match
I got a string (str1) and I want to extract anything after pattern "mycode=",
local str1 = "ServerName/codebase/?mycode=ABC123";
local tmp1 = string.match(str1, "mycode=%w+");
local tmp2 = string.gsub(tmp1,"mycode=", "");
From the logs,
tmp1 => mycode=ABC123
tmp2 => ABC123
Is there a better/more efficient way to do this? I do belive lua strings do not follow the POSIX standard (due to the size of the code base).
Yes, use a capture in your pattern to control what you get back from string.match.
From the lua reference manual (emphasis mine):
Looks for the first match of pattern in the string s. If it finds one, then match returns the captures from the pattern; otherwise it returns nil. If pattern specifies no captures, then the whole match is returned. A third, optional numerical argument init specifies where to start the search; its default value is 1 and can be negative.
It works like this:
> local str1 = "ServerName/codebase/?mycode=ABC123"
> local tmp1 = string.match(str1, "mycode=%w+")
> print(tmp1)
mycode=ABC123
> local tmp2 = string.match(str1, "mycode=(%w+)")
> print(tmp2)
ABC123
Say I have a string.
"poop"
I want to change "poop" to "peep".
In fact, I also want all of the o's in poop to change to e's for any word I put in.
Here's my attempt to do the above.
def getword():
x = (input("Please enter a word."))
return x
def main():
y = getword()
for i in range (len(y)):
if y[i] == "o":
y = y[:i] + "e"
print (y)
main()
As you can see, when you run it, it doesn't amount to what I want. Here is my expected output.
Enter a word.
>>> brother
brether
Something like this. I need to do it using slicing. I just don't know how.
Please keep your answer simple, since I'm somewhat new to Python. Thanks!
This uses slicing (but keep in mind that slicing is not the best way to do it):
def f(s):
for x in range(len(s)):
if s[x] == 'o':
s = s[:x]+'e'+s[x+1:]
return s
Strings in python are non-mutable, which means that you can't just swap out letters in a string, you would need to create a whole new string and concatenate letters on one-by-one
def getword():
x = (input("Please enter a word."))
return x
def main():
y = getword()
output = ''
for i in range(len(y)):
if y[i] == "o":
output = output + 'e'
else:
output = output + y[i]
print(output)
main()
I'll help you this once, but you should know that stack overflow is not a homework help site. You should be figuring these things out on your own to get the full educational experience.
EDIT
Using slicing, I suppose you could do:
def getword():
x = (input("Please enter a word."))
return x
def main():
y = getword()
output = '' # String variable to hold the output string. Starts empty
slice_start = 0 # Keeps track of what we have already added to the output. Starts at 0
for i in range(len(y) - 1): # Scan through all but the last character
if y[i] == "o": # If character is 'o'
output = output + y[slice_start:i] + 'e' # then add all the previous characters to the output string, and an e character to replace the o
slice_start = i + 1 # Increment the index to start the slice at to be the letter immediately after the 'o'
output = output + y[slice_start:-1] # Add the rest of the characters to output string from the last occurrence of an 'o' to the end of the string
if y[-1] == 'o': # We still haven't checked the last character, so check if its an 'o'
output = output + 'e' # If it is, add an 'e' instead to output
else:
output = output + y[-1] # Otherwise just add the character as-is
print(output)
main()
Comments should explain what is going on. I'm not sure if this is the most efficient or best way to do it (which really shouldn't matter, since slicing is a terribly inefficient way to do this anyways), just the first thing I hacked together that uses slicing.
EDIT Yeah... Ourous's solution is much more elegant
Can slicing even be used in this situation??
The only probable solution I think would work, as MirekE stated, is y.replace("o","e").
The code given below is to convert binary files from float32 to 16b with scale factor of 10. I am getting error of invalidation of %d.
setwd("C:\\2001")
for (b in paste("data", 1:365, ".flt", sep="")) {
conne <- file(b, "rb")
file1<- readBin(conne, double(), size=4, n=360*720, signed=TRUE)
file1[file1 != -9999] <- file1[file1 != -9999]*10
close(conne)
fileName <- sprintf("C:\\New folder (11)\\NewFile%d.bin", b)
writeBin(as.integer(file1), fileName, size = 2)
}
Result:
Error in sprintf("C:\\New folder (11)\\NewFile%d.bin", :
invalid format '%d'; use format %s for character objects
I used %s as suggested by R.But the files from 1:365 were totally empty
The %d is a placeholder for a integer variable inside a string. Therefore, when you use sprintf(%d, var), var must be an integer.
In your case, the variable b is a string (or a character object). So, you use the placeholder for string variables, which is %s.
Now, if your files are empty, there must be something wrong elsewhere in your code. You should ask another question more specific to it.