Using Folium to visulize PCA image raise "Error expected type string, actual type long,actual value 1

Question

This is how I get the PCs at the specified scale and in the specified region:

# Get the Principal Components (PCs) 

pcImage = getPrincipalComponents(centered, scale, region) #this return PCA image 
# Plot each PC as a new layer
for i in range(bandNames.length().getInfo()):
    band = pcImage.bandNames().get(i)
    map.addLayer(pcImage.select(['band']),{'min':-2,'max':2},'band')

Here is the pca functionin which am passing an ee image:

 # Principal Components (PC) in the region as a new image.
def getPrincipalComponents(centered, scale, region):
    #Collapse the bands of the image into a 1D array per pixel
    arrays = centered.toArray()
    #Compute the covariance of the bands within the region.
    covar=arrays.reduceRegion(
        reducer=ee.Reducer.centeredCovariance(),
        geometry=region,
        scale=scale,
        maxPixels=1e9)

    #Get the 'array' covariance result and cast to an array.
    # This represents the band-to-band covariance within the region.
    covarArray = ee.Array(covar.get('array'))
    #Perform an eigen analysis and slice apart the values and vectors.
    eigens = covarArray.eigen()
    # This is a P-length vector of Eigenvalues.
    eigenValues = eigens.slice(1, 0, 1)
    # This is a PxP matrix with eigenvectors in rows.
    eigenVectors = eigens.slice(1, 1)
    # Convert the array image to 2D arrays for matrix computations.
    arrayImage = arrays.toArray(1)
    #Left multiply the image array by the matrix of eigenvectors.
    principalComponents = ee.Image(eigenVectors).matrixMultiply(arrayImage)
    # Turn the square roots of the Eigenvalues into a P-band image.
    sdImage = ee.Image(eigenValues.sqrt())\
        .arrayProject([0]).arrayFlatten([getNewBandNames('sd')])
    # Turn the PCs into a P-band image, normalized by SD.
    # Throw out an an unneeded dimension, [[]] -> [].
    # Make the one band array image a multi-band image, [] -> image.
    # Normalize the PCs by their SDs.
    return principalComponents\
        .arrayProject([0])\
        .arrayFlatten([getNewBandNames('pc')])\
        .divide(sdImage)