startswith

Python – Use multiple str.startswith() in a for loop get their specific values Question: The below function parses multiple csv files in a directory and takes out values using str.startwith(). It works find using ‘firstline.startswith(‘TrakPro’)‘ and ‘txt.startswith(‘Serial’)‘. However, when I add a third str.startwith() i.e. txt2.startswith(‘Test’), nothing prints out, no error, appears to ignore it. …

startswith() in Python acting unexpectedly Question: I have the following simple Python code that support to ask if a player wants to play the game again or not. print(‘Do you want to play again? (yes or no)’) if not input(‘> ‘.lower().startswith(‘y’)): print(‘no’) else: print(‘yes’) However, it does not work correctly. When I run it, it …

How to skip rows from a file until a specific string without using any input code? Question: I have a txt file name ‘test.txt’ and want to skip the first rows until I get to the line with the string “~A”. At this line, I want to remove “~A” and create a dataframe with 3 …

Why is string's startswith slower than in? Question: Surprisingly, I find startswith is slower than in: In [10]: s=”ABCD”*10 In [11]: %timeit s.startswith(“XYZ”) 1000000 loops, best of 3: 307 ns per loop In [12]: %timeit “XYZ” in s 10000000 loops, best of 3: 81.7 ns per loop As we all know, the in operation needs …

Does R have function startswith or endswith like python? Question: > startsWith(‘abc’, ‘a’) [1] TRUE > startsWith(‘abc’, ‘c’) [1] FALSE > endsWith(‘abc’, ‘a’) [1] FALSE > endsWith(‘abc’, ‘c’) [1] TRUE Asked By: chen || Source Answers: Not inbuilt like that. Options include grepl and substr. x <- ‘ABCDE’ grepl(‘^AB’, x) # starts with AB? grepl(‘DE$’, …

Case-insensitive string startswith in Python Question: Here is how I check whether mystring begins with some string: >>> mystring.lower().startswith(“he”) True The problem is that mystring is very long (thousands of characters), so the lower() operation takes a lot of time. QUESTION: Is there a more efficient way? My unsuccessful attempt: >>> import re; >>> mystring.startswith(“he”, …

Why is startswith slower than slicing Question: Why is the implementation of startwith slower than slicing? In [1]: x = ‘foobar’ In [2]: y = ‘foo’ In [3]: %timeit x.startswith(y) 1000000 loops, best of 3: 321 ns per loop In [4]: %timeit x[:3] == y 10000000 loops, best of 3: 164 ns per loop Surprisingly, …

What is the easiest way to get all strings that do not start with a character? Question: I am trying to parse about 20 million lines from a text file and am looking for a way to do some further manipulations on lines that do not start with question marks. I would like a solution …