I've been working with data imported from a CSV. Pandas changed some columns to float, so now the numbers in these columns get displayed as floating points! However, I need them to be displayed as integers or without comma. Is there a way to convert them to integers or not display the comma?
df.col = df.col.astype(int)
df = df.astype(int)
To modify the float output do this:
df= pd.DataFrame(range(5), columns=['a'])
df.a = df.a.astype(float)
df
Out[33]:
a
0 0.0000000
1 1.0000000
2 2.0000000
3 3.0000000
4 4.0000000
pd.options.display.float_format = '{:,.0f}'.format
df
Out[35]:
a
0 0
1 1
2 2
3 3
4 4
Use the pandas.DataFrame.astype(<type>)
function to manipulate column dtypes.
>>> df = pd.DataFrame(np.random.rand(3,4), columns=list("ABCD"))
>>> df
A B C D
0 0.542447 0.949988 0.669239 0.879887
1 0.068542 0.757775 0.891903 0.384542
2 0.021274 0.587504 0.180426 0.574300
>>> df[list("ABCD")] = df[list("ABCD")].astype(int)
>>> df
A B C D
0 0 0 0 0
1 0 0 0 0
2 0 0 0 0
EDIT:
To handle missing values:
>>> df
A B C D
0 0.475103 0.355453 0.66 0.869336
1 0.260395 0.200287 NaN 0.617024
2 0.517692 0.735613 0.18 0.657106
>>> df[list("ABCD")] = df[list("ABCD")].fillna(0.0).astype(int)
>>> df
A B C D
0 0 0 0 0
1 0 0 0 0
2 0 0 0 0
Considering the following data frame:
>>> df = pd.DataFrame(10*np.random.rand(3, 4), columns=list("ABCD"))
>>> print(df)
... A B C D
... 0 8.362940 0.354027 1.916283 6.226750
... 1 1.988232 9.003545 9.277504 8.522808
... 2 1.141432 4.935593 2.700118 7.739108
Using a list of column names, change the type for multiple columns with applymap()
:
>>> cols = ['A', 'B']
>>> df[cols] = df[cols].applymap(np.int64)
>>> print(df)
... A B C D
... 0 8 0 1.916283 6.226750
... 1 1 9 9.277504 8.522808
... 2 1 4 2.700118 7.739108
Or for a single column with apply()
:
>>> df['C'] = df['C'].apply(np.int64)
>>> print(df)
... A B C D
... 0 8 0 1 6.226750
... 1 1 9 9 8.522808
... 2 1 4 2 7.739108
ValueError: ('cannot convert float NaN to integer', u'occurred at index <column_name>')
df['C'] = df['C'].dropna().apply(np.int64)
To convert all float columns to int
>>> df = pd.DataFrame(np.random.rand(5, 4) * 10, columns=list('PQRS'))
>>> print(df)
... P Q R S
... 0 4.395994 0.844292 8.543430 1.933934
... 1 0.311974 9.519054 6.171577 3.859993
... 2 2.056797 0.836150 5.270513 3.224497
... 3 3.919300 8.562298 6.852941 1.415992
... 4 9.958550 9.013425 8.703142 3.588733
>>> float_col = df.select_dtypes(include=['float64']) # This will select float columns only
>>> # list(float_col.columns.values)
>>> for col in float_col.columns.values:
... df[col] = df[col].astype('int64')
>>> print(df)
... P Q R S
... 0 4 0 8 1
... 1 0 9 6 3
... 2 2 0 5 3
... 3 3 8 6 1
... 4 9 9 8 3
This is a quick solution in case you want to convert more columns of your pandas.DataFrame
from float to integer considering also the case that you can have NaN values.
cols = ['col_1', 'col_2', 'col_3', 'col_4']
for col in cols:
df[col] = df[col].apply(lambda x: int(x) if x == x else "")
I tried with else x)
and else None)
, but the result is still having the float number, so I used else ""
.
""
to all the values in col
Expanding on @Ryan G mentioned usage of the pandas.DataFrame.astype(<type>)
method, one can use the errors=ignore
argument to only convert those columns that do not produce an error, which notably simplifies the syntax. Obviously, caution should be applied when ignoring errors, but for this task it comes very handy.
>>> df = pd.DataFrame(np.random.rand(3, 4), columns=list('ABCD'))
>>> df *= 10
>>> print(df)
... A B C D
... 0 2.16861 8.34139 1.83434 6.91706
... 1 5.85938 9.71712 5.53371 4.26542
... 2 0.50112 4.06725 1.99795 4.75698
>>> df['E'] = list('XYZ')
>>> df.astype(int, errors='ignore')
>>> print(df)
... A B C D E
... 0 2 8 1 6 X
... 1 5 9 5 4 Y
... 2 0 4 1 4 Z
From pandas.DataFrame.astype docs:
errors : {‘raise’, ‘ignore’}, default ‘raise’ Control raising of exceptions on invalid data for provided dtype. raise : allow exceptions to be raised ignore : suppress exceptions. On error return original object New in version 0.20.0.
The columns that needs to be converted to int can be mentioned in a dictionary also as below
df = df.astype({'col1': 'int', 'col2': 'int', 'col3': 'int'})
>>> import pandas as pd
>>> right = pd.DataFrame({'C': [1.002, 2.003], 'D': [1.009, 4.55], 'key': ['K0', 'K1']})
>>> print(right)
C D key
0 1.002 1.009 K0
1 2.003 4.550 K1
>>> right['C'] = right.C.astype(int)
>>> print(right)
C D key
0 1 1.009 K0
1 2 4.550 K1
Use 'Int64' for NaN support
astype(int) and astype('int64') cannot handle missing values (numpy int)
astype('Int64') can handle missing values (pandas int)
df['A'] = df['A'].astype('Int64') # capital I
This assumes you want to keep missing values as NaN. If you plan to impute them, you could fillna
first as Ryan suggested.
Examples of 'Int64' (capital I)
If the floats are already rounded, just use astype: df = pd.DataFrame({'A': [99.0, np.nan, 42.0]})
df['A'] = df['A'].astype('Int64')
# A
# 0 99
# 1
Notes
'Int64' is an alias for Int64Dtype: df['A'] = df['A'].astype(pd.Int64Dtype()) # same as astype('Int64')
Sized/signed aliases are available: lower bound upper bound 'Int8' -128 127 'Int16' -32,768 32,767 'Int32' -2,147,483,648 2,147,483,647 'Int64' -9,223,372,036,854,775,808 9,223,372,036,854,775,807 'UInt8' 0 255 'UInt16' 0 65,535 'UInt32' 0 4,294,967,295 'UInt64' 0 18,446,744,073,709,551,615
In the text of the question is explained that the data comes from a csv. Só, I think that show options to make the conversion when the data is read and not after are relevant to the topic.
When importing spreadsheets or csv in a dataframe, "only integer columns" are commonly converted to float because excel stores all numerical values as floats and how the underlying libraries works.
When the file is read with read_excel or read_csv there are a couple of options avoid the after import conversion:
parameter dtype allows a pass a dictionary of column names and target types like dtype = {"my_column": "Int64"}
parameter converters can be used to pass a function that makes the conversion, for example changing NaN's with 0. converters = {"my_column": lambda x: int(x) if x else 0}
parameter convert_float will convert "integral floats to int (i.e., 1.0 –> 1)", but take care with corner cases like NaN's. This parameter is only available in read_excel
To make the conversion in an existing dataframe several alternatives have been given in other comments, but since v1.0.0 pandas has a interesting function for this cases: convert_dtypes, that "Convert columns to best possible dtypes using dtypes supporting pd.NA."
As example:
In [3]: import numpy as np
In [4]: import pandas as pd
In [5]: df = pd.DataFrame(
...: {
...: "a": pd.Series([1, 2, 3], dtype=np.dtype("int64")),
...: "b": pd.Series([1.0, 2.0, 3.0], dtype=np.dtype("float")),
...: "c": pd.Series([1.0, np.nan, 3.0]),
...: "d": pd.Series([1, np.nan, 3]),
...: }
...: )
In [6]: df
Out[6]:
a b c d
0 1 1.0 1.0 1.0
1 2 2.0 NaN NaN
2 3 3.0 3.0 3.0
In [7]: df.dtypes
Out[7]:
a int64
b float64
c float64
d float64
dtype: object
In [8]: converted = df.convert_dtypes()
In [9]: converted.dtypes
Out[9]:
a Int64
b Int64
c Int64
d Int64
dtype: object
In [10]: converted
Out[10]:
a b c d
0 1 1 1 1
1 2 2 <NA> <NA>
2 3 3 3 3
pandas
>= 1.0. Thanks so much!
Although there are many options here, You can also convert the format of specific columns using a dictionary
Data = pd.read_csv('Your_Data.csv')
Data_2 = Data.astype({"Column a":"int32", "Column_b": "float64", "Column_c": "int32"})
print(Data_2 .dtypes) # Check the dtypes of the columns
This is an useful and very fast way to change the data format of specific columns for quick data analysis.
Success story sharing
df.a = df.a.astype(float)
? Does this make a copy (not sure how thecopy
param toastype()
is used) ? Anyway to update the type "in place" ?DF.({'200': {'#': 354, '%': 0.9971830985915493}, '302': {'#': 1, '%': 0.0028169014084507044}})
Note the # get converted to float and they are rows, not columns. because each is aSeries
which can only store a single uniform type?dtype
? If it'sdtype
then you need to create those columns asdtype
object
so it allows mixed, otherwise my advice would be to just use float and when doing comparisons usenp.isclose
#
above should remain ints, while the%
are typically floats.