when my function f is called with a variable I want to check if var is a pandas dataframe:
def f(var):
if var == pd.DataFrame():
print "do stuff"
I guess the solution might be quite simple but even with
def f(var):
if var.values != None:
print "do stuff"
I can't get it to work like expected.
Use isinstance, nothing else:
if isinstance(x, pd.DataFrame):
... # do something
PEP8 says explicitly that isinstance is the preferred way to check types
No: type(x) is pd.DataFrame
No: type(x) == pd.DataFrame
Yes: isinstance(x, pd.DataFrame)
And don't even think about
if obj.__class__.__name__ = 'DataFrame':
expect_problems_some_day()
isinstance handles inheritance (see What are the differences between type() and isinstance()?). For example, it will tell you if a variable is a string (either str or unicode), because they derive from basestring)
if isinstance(obj, basestring):
i_am_string(obj)
Specifically for pandas DataFrame objects:
import pandas as pd
isinstance(var, pd.DataFrame)
Use the built-in isinstance() function.
import pandas as pd
def f(var):
if isinstance(var, pd.DataFrame):
print("do stuff")
import pandas as pd, but instead just import pandas? Just perform an or on both possibilities, or is there something more sophisticated I don't know of?
import pandas.DataFrame as panda_type and then inside then check the array type using isinstance(var, panda_type)Or you can use the simplest solution: type(x).
If it is Data Frame it will output pandas.core.frame.DataFrame.
varis equal to an empty dataframe". What you really want is "if the type ofvaris equal to the typepd.DataFrame". You can check that usingisinstance