operations with empty strings | ljust () function: StackOverflow Questions

Answer #1

You can do this with str.ljust(width[, fillchar]):

Return the string left justified in a string of length width. Padding is done using the specified fillchar (default is a space). The original string is returned if width is less than len(s).

>>> "hi".ljust(10)
"hi        "

Answer #2

For many objects, you can use this code, replacing "object" with the object you"re interested in:

object_methods = [method_name for method_name in dir(object)
                  if callable(getattr(object, method_name))]

I discovered it at diveintopython.net (now archived). Hopefully, that should provide some further detail!

If you get an AttributeError, you can use this instead:

getattr( is intolerant of pandas style python3.6 abstract virtual sub-classes. This code does the same as above and ignores exceptions.

import pandas as pd
df = pd.DataFrame([[10, 20, 30], [100, 200, 300]],
                  columns=["foo", "bar", "baz"])
def get_methods(object, spacing=20):
  methodList = []
  for method_name in dir(object):
    try:
        if callable(getattr(object, method_name)):
            methodList.append(str(method_name))
    except:
        methodList.append(str(method_name))
  processFunc = (lambda s: " ".join(s.split())) or (lambda s: s)
  for method in methodList:
    try:
        print(str(method.ljust(spacing)) + " " +
              processFunc(str(getattr(object, method).__doc__)[0:90]))
    except:
        print(method.ljust(spacing) + " " + " getattr() failed")

get_methods(df["foo"])

Answer #3

a += [""] * (N - len(a))

or if you don"t want to change a in place

new_a = a + [""] * (N - len(a))

you can always create a subclass of list and call the method whatever you please

class MyList(list):
    def ljust(self, n, fillvalue=""):
        return self + [fillvalue] * (n - len(self))

a = MyList(["1"])
b = a.ljust(5, "")