I have a program which writes a user’s highscore to a text file. The file is named by the user when they choose a playername.
If the file with that specific username already exists, then the program should append to the file (so that you can see more than one highscore). And if a file with that username doesn’t exist (for example, if the user is ….
I want to do something like this:
myList = [10, 20, 30]
yourList = myList.append(40)
Unfortunately, list append does not return the modified list.
So, how can I allow append to return the new list?
See also: Why do these list operations (methods) return None, rather than the resulting list?
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How to concatenate two dictionaries to create a new one? [duplicate]
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Closed 7 years ago.
I have two dictionaries and I’d like to be able to make them one:
Something like th….
Why do these two operations (append() resp. +) give different results?
>>> c = [1, 2, 3]
>>> c
[1, 2, 3]
>>> c += c
>>> c
[1, 2, 3, 1, 2, 3]
>>> c = [1, 2, 3]
>>> c.append(c)
>>> c
[1, 2, 3, […]]
>>>
In the last case there’s actually an infinite recursion. c[-1] and c are the same. Why is it different with the + operation?
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So I have initialized an empty pandas DataFrame and I would like to iteratively append lists (or Series) as rows in this DataFrame. What is the best way of doing this?
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Given two lists:
x = [1,2,3]
y = [4,5,6]
What is the syntax to:
Insert x into y such that y now looks like [1, 2, 3, [4, 5, 6]]?
Insert all the items of x into y such that y now looks like [1, 2, 3, 4, 5, 6]?
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How do I add values to an existing set?
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How do I efficiently append one string to another? Are there any faster alternatives to:
var1 = “foo”
var2 = “bar”
var3 = var1 + var2
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How do I create an empty DataFrame, then add rows, one by one?
I created an empty DataFrame:
df = pd.DataFrame(columns=(‘lib’, ‘qty1’, ‘qty2′))
Then I can add a new row at the end and fill a single field with:
df = df._set_value(index=len(df), col=’qty1’, value=10.0)
It works for only one field at a time. What is a better way to add new row to d….
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What’s the difference between the list methods append() and extend()?
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