Matplotlib pyplot.title(string) returns error

Question

When I call pyplot.title('some string') it throws the exception, 'str' object is not callable'. I copied the following from the matplotlib online documentation:

mu, sigma = 100, 15 x = mu + sigma * np.random.randn(10000)  # the histogram of the data n, bins, patches = plt.hist(x, 50, normed=1, facecolor='g', alpha=0.75)   plt.xlabel('Smarts') plt.ylabel('Probability') plt.title('Histogram of IQ') plt.text(60, .025, r'$\mu=100,\ \sigma=15$') plt.axis([40, 160, 0, 0.03]) plt.grid(True) plt.show() 

and get

TypeError                                 Traceback (most recent call last) <ipython-input-158-40fe7a831b06> in <module>()       8 plt.xlabel('Smarts')       9 plt.ylabel('Probability') ---> 10 plt.title('Histogram of IQ')      11 plt.text(60, .025, r'$\mu=100,\ \sigma=15$')      12 plt.axis([40, 160, 0, 0.03])  TypeError: 'str' object is not callable 

pyplot.suptitle() works OK

I'm using python 2.7.5 and the latest release of matplotlib on an iMac with an I7 processor OSX 10.8 and 8 gig ram and ipython notebook.

Does anyone know what's going on?

Answer 1

It happened to me because I tried to do plot.title = "Some string" so that rewrote the title() method. That's the exact reason why it happens :) . As others have said you just need to restart the kernel, no need to reinstall.

Answer 2

I had the same problem. The code was fine, but in the interpreter, I had previoulsy used incorrect xlabel() calls. re-starting the interpreter (close and reopen it) was enough for me, no need to reinstall all python/matplotlib !