Dataframe Change Column type

An error occurred today in the process of finding the inverse of a matrix using the NumPy Linalg.det ():
Typeerror:no loop matching the specified signature and casting is found for Ufunc
Check a half-day found is the problem of data types,numpy in the inverse of the time will first check the data type is consistent, if inconsistent will be an error (say this wrong message is too difficult to understand, but also look at the source O (╯-╰) o).
Because my data is used pandas. Dataframe read, so the data type of each column may be different.
Back to check the data, sure enough to have some int, some float. So all changed to float64 type.
The following methods were found, as well as the Dataframe data type: dataframe type conversion Method-astype ()

Import pandas as PD
DF = PD. Dataframe ([{' col1 ': ' A ', ' col2 ': ' 1 '}, {' col1 ': ' B ', ' col2 ': ' 2 '}]) print df.dtypes df[' col2 '

] = df[' col2 ']. Astype (' int ')
print '-----------'
print df.dtypes

df[' col2 '] = df[' col2 '].astype (' float64 ')
print ' -----------'
print df.dtypes

Output:

Col1    Object
col2    object
dtype:object
-----------
col1    Object
col2     int32
dtype:object
-----------
col1     object
col2    float64
dtype:object

Astype () can also change the type of all data at once:

In[30]:a
out[31]: 
          a         b         c         d
0  0.891380  0.442167-0.539450  1.023458
1- 0.488131-1.847104-0.209799-0.768713
2  1.290434  0.327096  0.358406  0.422209

in[32] : A.astype (' int32 ')
out[32]: 
   a  b  c  d
0  0  0  0  1  1 0- 1  0  0
2  1  0 0 0

Attached: Data Type list

The Data type Description bool_ Boolean (True or False) stored as a byte int_ Default integer type (same as C long; nor Mally either Int64 or Int32) Intc identical to C int (normally int32 or Int64) intp Integer used for indexing (same As C ssize_t; Normally either Int32 or Int64) int8 Byte ( -128 to 127) Int16 integer ( -32768 to 32767) Int32 integer (-2147483648 to 2147483647) Int64 integer ( -9223372036854775808 to 9223372036854775807) uint8 Unsigned Integer (0 to 255) uint16 U nsigned Integer (0 to 65535) uint32 Unsigned Integer (0 to 4294967295) UInt64 Unsigned integer (0 to 1844674407370955161
5) Float_ shorthand for float64.  Float16 Half Precision Float:sign bit, 5 bits exponent, ten bits mantissa float32 single precision bit, 8 bits Exponent bits mantissa float64 Double precision float:sign bit, one bits exponent, bits mantissa complex_ short
Hand for complex128. complex64 Complex number, represented by two 32-bit floats (real and ImaginARY Components complex128 Complex number, represented by two 64-bit floats (real and imaginary components)